Skill Branches are one of the most interesting, as they give unique abilities and buffs nothing else can. Optimizing them is crucial to getting the edge in big battles. By default, every character has three skill branches, but it is possible to unlock two more for each character throughout the game, pushing their potential through the roof. Each character's 4th skill branch can be unlocked throughout the bulk of the story, while the 5th skill branches require reaching Chapter 16 in the story to unlock.
It says a lot about Shulk's character that Pessimism isn't a trait he has by default. This branch is great for reducing enemy aggro on Shulk, allowing him to move around enemies and strike them where needed, as well as granting immunity to some debuffs.
The quest to unlock it is in Colony 9. It requires a 4 & a half star affinity with Colony 9 and for the story to have progressed to at least Satorl Marsh. Increasing area affinity is simply a matter of talking to people and doing quests. Talk to Désirée with Shulk as the party lead and listen to their very long story. They'll ask you to make a choice for them, and either way, players will unlock the Pessimism branch.
Shulk's final skill branch has a wide range of uses. It provides a passive critical hit rate boost as more skills are unlocked. The skills themselves are very well-rounded. They boost EXP gain, trading bonuses, defence, agility and Talent Gauge filling.
As affinity with Colony 9 rises, new instalments in the questline of a young military captain, Emmy Leater, will unlock. The final of these quests will depend on the ending the player chose in "A Young Captain's Challenge". One quest is more complex than the other. Either way, talk to Miller with Shulk in the lead once 4 & a half star affinity with Colony 9 is reached. The quest started will either be called "A Young Captain's Trust" or "A Young Captain's Revival".
"A Young Captain's Trust" simply requires finding & talking to Emmy, who is at the Mining Base of the Ether Mine. "A Young Captain's Revival" involves solving the mystery of where a poisoned blade came from. Players must gather four Poisonous Gourds from Satorl Marsh, talk to Emmy, Kantz & Raoul to hear their stories before returning to Miller and making an accusation. It doesn't matter who the player picks, as the outcome is the same, but Kantz is the correct answer. Once this is done, Bravery is unlocked.
An extremely powerful branch for any Reyn user, Impatience is all about getting Reyn to hit way more often. He gets a better counter-attacking chance; Haste buffs, double attacks & quicker Talent Gauge filling. When this branch is maxed out, Reyn will become a tornado of strong attacks.
Unlocking it requires completing the Cook-Off Showdown! quest. This is the finale of a quest chain, all involving a Cook-Off in Colony 6. Make sure every quest in this chain is complete, have Reyn as the party leader, and players have access to Valak Mountain. Talk to Ma'crish once affinity with Colony 6 is 2 & a half stars, and Hoko will ask you to kill Entma Kings on Valak Mountain to get two Soya Paste Shells. Make a final choice for Hoko, and Impatience will be unlocked.
Like Shulk's final branch, Reyn's has quite a variety of boosts. Physical Defence gets boosted significantly, making Reyn even bulkier than before. On top of that, Reyn gains the ability to heal the party after Chain Attacks, gets greater Haste and becomes stronger when party members get KO'ed.
Once Colony 9 is at 4 & a half star affinity, have Reyn lead the party and speak to Moritz. They will send the player out to gather some rare resources. To do this, players must enter an extremely high-level area of Tephra Cave that has been blocked off until now. Enemies as high as level 95 must be defeated, but once that's done, return to Moritz, and Camaraderies will unlock.
Sharla's capabilities as a healer make her almost vital to have in the party for the whole game. This skill tree makes sure she can stay in the fight as long as possible. Both her physical & ether defenses will be boosted, as will her block & counter-attack rates.
Once a 4-star affinity with Central Bionis is reached, put Sharla in the front of the party and talk to Rasha in Frontier Village. She will have a couple of pre-requisite quests, but eventually, the "Avenge a Mamapon's Death" quest will start. Rasha will direct you to the Eryth Sea, where you must defeat a unique Pillager Hode enemy. Return to Frontier Village and show the Cloth Shred to Cherri, and Reliance will be unlocked.
Sharla's final skill branch is all about pushing her restorative efforts as far as they can go. Sharla's own HP will grow with this branch, and all of the skills themselves are about increasing her HP output when healing and a little extra for increasing ether defence.
Getting this branch requires beating a questline which is ever so slightly different depending on who the player invites to the restored Colony 6. Both En Argentis or Zel Argentis can be invited once housing is at Level 5, but only one of them, and whichever one the player picks will be the one they do the questline with. The questline follows largely the same thread, but with slightly different people & locations along the way.
To start the questline, put Sharla in the party leader slot after the player has reached Chapter 16. Then, invite either Oleksiy or Peppino to Colony 6 (both can be invited regardless of this questline) once housing is at Level 4. Then get Colony 6 affinity to 3 & a half stars and talk to either Zel or En. Each quest in the questline has slightly higher affinity requirements than the last. Once that's all done, Sharla will unlock Affection.
Dunban is an interesting fighter, acting as a speedy attacker who can draw aggro and evade attacks. His biggest downside is a low HP pool, and this branch does its best to supplement that. His physical defence will be boosted, and equipment weight will be reduced, allowing him to wear heavier armor to survive bigger hits.
Dunban must be in the lead to activate this quest. It has no affinity requirements. However, there are pre-requisite quests that involve saving a trapped Nopon from behind a wall of ice in Valak Mountain. Eventually, this Nopon, Dakuku, will give "The Balance Of Power" quest. This is a simple but tough quest that involved defeating two unique monsters. Once the Barbaric Sitri & Banquet Vassago are slain, return to Dakuku and Obstinance will unlock.
Dunban's final skill branch has a split focus between hitting hard & often and building up the party. Strength is increased with this skill branch, and a couple of skills give haste buffs and increased counter-attack chance. The rest of the skills focus on building tension and quickly filling the Party Gauge for Chain Attacks.
To start the required quest, players will need to continue to story a little way into Chapter 16, after Colony 6 is attacked. Once there, put Dunban as the party leader, make sure Vronik in the Hidden Machina Village has been spoken to, and affinity with Hidden Village is 3 & a half stars. Talk to Orkatix, and three more quests will appear to collect parts from specified Mechons to build a device. Once this is done, oddly, Shulk must be the party leader when talking to Orkatix to complete the quest and unlock Enthusiasm.
Melia can be a powerful ether-based attacker if used right and her ability to inflict status conditions is very useful. This skill branch looks to boost her fairly abysmal defensive capabilities. Ether defence, HP & block rate are all boosted, and abilities to reduce aggro are included.
After completing Jarrack's questline at the Ether Plant in Eryth Sea, place Melia as the party leader and talk to Shalen at the top of Syrath Lighthouse, also in Eryth Sea. Completing the quest is a simple matter of defeating three Decay Ekidnos that spawn around the lighthouse at night. Once that is done, talk to Shalen and Reticence will unlock.
Melia's final skill branch looks to boost friendly status effects and debuff enemy ones. Ether will increase as the branch grows. With these skills, enemies like Telethia become easier to take down, and Spikes becomes less damaging to the party.
The questline for this can be started in two different ways. The beginning quests are available during the story while the party heads to the High Entia Tomb. However, if they are missed, a different route will become available upon reaching Chapter 16. Miriall, in the Ether Plant of Eryth Sea, will have two quests available, "The Missing Boy" isn't a part of the questline, but it must be accepted before "Investigating Satorl" becomes available.
To complete "Investigating Satorl", first defeat a level 35 Dogmatic Gogol in Satorl Marsh, then speak to Talia, once in the Marsh and once in the Ether Plant. After that is completed, Melia must be the party leader, and Upper Bionis must have an affinity of 2 & a half stars. Then "Ancient High Entia Mystery" will begin. The quest will point towards a statue on Valak Mountain. Interacting with it will spawn a Level 97-99 monster; however, it doesn't have to be defeated. Players can instead run away and talk to Talia to complete the quest and unlock Passion.
Despite what his small stature may suggest, Riki is the tankiest party member by some margin, and his combat focuses on stacking status effects onto the enemy. The unfortunately named Cowardice branch looks to increase his chance of not taking hits and staying in the fight. Boosts to block rate & agility are extremely useful, and there are a few skills to make attacks more powerful too.
Once an affinity of 3 & a half stars is reached in Central Bionis and the player has access to Valak Mountain, make Riki the party leader and talk to Dabidabi. As long as Adidi has been spoken to, the quest "Getting Bigger!" will start. This is a bit of a complicated quest, and the path to success isn't always clear.
First, speak to Adidi, who is around on the north bank of the Reservoir from 18:00 to 6:00. Then, obtain five Ekidno Jaw Gristle. These are most commonly obtained from Ekidno around the Eryth Sea. However, they are available as a trade item from a couple of NPCs. Finally, chat to Puko, who will be by the weapons shop in Frontier Village between 9:00 & 15:00. This will trigger the "Who Is Bigger?" quest. Complete that by talking to either Adidi or Dabidabi, and Cowardice will be unlocked.
Riki's final branch is another wide-ranging one. Critical hit rate increase as the skill grows. The first skill allows Riki to wear heavy armor, making him even tankier than before. Other skills increase Strength, increase the power of Spikes, reduce Party Gauge usage and resist debuffs.
Unlocking this branch requires completing a long questline that will span from the mid-game to almost the very end. The first quest can be started by talking to Pipiki in Frontier Village after Riki has joined the party. The majority of the rest of the questline will become available once the Eryth Sea has been reached, and they all centre around a Nopon Sage.
The finale of this questline unlocks once Chapter 16 is reached, Riki is the party leader, and Central Bionis has an affinity of 3 & a half stars. The quest requires the player to defeat a Level 96 Unreliable Rezno monster. It's tough, but once it's done, Heroism will unlock.
Fiora is a character focused on offence. They don't hit as hard as Shulk, but they hit much faster and look to chain powerful attacks together. This skill branch looks to get even more attacks in the mix at greater power. It increases their counter-attack rate along with their critical hit rate and the speed of the Talent Gauge.
To unlock this branch, first complete Rizika's questline about their house, raise affinity with Hidden Village to 2 stars and have access to Mechonis Fields. Then, with Fiora in the lead, talk to Karlos in Hidden Machina Village. They will direct you to the Power Pipe Ruins in Fallen Arm, where the Oath Sword can be found. Retrieve it and bring it back to Karlos to unlock the Rashness branch.
Fiora's final skill tree is thematically appropriate and kind of cute, as all of the skills require her to be fighting alongside Shulk. Her Ether Defence grows with this skill, and the abilities increase her Arts damage, HP restores, Chain Attack damage and buff to all stats; but only when Shulk is also in the party.
This short questline can be started as soon as Chapter 16 is reached with no other requirements. Talk to Dulland on Junks, which has landed close to Colony 6, and he will give the "Securing Provisions" quest. Completing that and the following "A Flower For Rose" quest and the finale of the questline will be immediately given if Fiora is in the lead. The "Battling Brutes" quest is arguably the hardest in the entire game as it requires battling two Level 98 enemies simultaneously.
Return to Dulland once it is done, and Fiora's Innocence will be unlocked.