Hexers are the disabler class, with a few debuffs added into their skillset for good measure. Their job is to roll the dice and try to inflict disables on enemies. If they succeed, your life gets considerably easier in fights, since basically every disable they have access to is useful. However, conversely, if they fail, then you've basically wasted one of your turns on precisely nothing. They're a bit all-or-nothing like that.


(Full stat table)

Common Passives HP Up, TP Up
Gathering Skill Chop

Hexers have exactly the stats you'd expect from a disabler class: high TEC and LUC (they also, fairly obviously, have the best infliction score of any of the classes), high TP, okay AGI, and garbage HP, STR, and VIT.

Curse Mastery

Required to learn Curse skills. Increases the effective infliction rate (ie. after calculations involving TEC and LUC have been done) of Curse skills.

Sapping Curse

Reduces all enemies' attack for a set amount of turns. Has no speed modifier at all levels.
Attack debuffs have a bit more utility than defense buffs, in my opinion, because enemy debuff slots are generally not as valuable as party buff slots. You could do worse for prolonging your party's lifespans than Sapping Curse. It's not like it has high requirements. On the other hand, Hexers are very, very hungry for skill points for their actual disables, so your skill points are probably better spent on disables.
The values on this seem somewhat low, but the damage cut can make the slight difference between eating a heavy hit and outright dying, which is all that matters.

Frailty Curse

Reduces all enemies' defense for a set amount of turns. Has no speed modifier at all levels.
Defense debuffs are really good, but like I mentioned with Sapping Curse, Hexers want most of their skill points in their disabling skills.
This is pretty good, but in my experience Hexer's turn economy is extremely cramped and more often than not you won't have the room to throw in something like this. It'd probably be pretty nice on a healer?

Leaden Curse

Reduces all enemies' speed for a set amount of turns. Has no speed modifier at all levels.
Speed buffs/debuffs are probably, like, the absolute worst modifier type in the game.
There's not much more to be said about speed modifiers. I don't recommend using this.

Deceit Curse

Reduces all enemies' accuracy for a set amount of turns. Has no speed modifier at all levels.
Ehhhhhhhhhh. I guess if you really want your Hexer to be a pure debuffer that focuses on making your party more survivable, Sapping Curse plus Deceit Curse isn't the worst combination of skills to focus on. On the other hand, literally any class could do that with these skills on Grimoires, so...
I guess you could try to incorporate this into some absurd Survivalist dodge setup? Maybe? Besides that it's fairly gimmicky and low rate and I wouldn't trust my life with it.

Revenge Curse

Deals ranged TEC-based almighty damage to one enemy. Revenge Curse's final damage is based on the result of running the base damage through the normal player TEC damage formula (this means buffs are applied before any calculations involving HP), and then multiplying it by a function of the player's max HP, their current HP, and what percentage of their maximum HP they currently have:

[1 + ((MaxHP - CurHP) * 20 / 10000] * [((Missing HP%) + (Missing HP% ^ 2) + 0.02) / 2]

Missing HP% = [100 - ((CurHP / MaxHP) * 100)] / 10

Has an 80% speed modifier and a base accuracy of 100% at all levels.
Revenge Curse is nowhere near as powerful as it was in the original EO2, where it first showed up, and frankly that's a really good thing. Its nerfs are mostly based on the fact that it's now based on normal player TEC damage, it's far harder to hit the HP cap in EOU than it was in EO2, and enemy HP totals are considerably higher in EOU than they were in EO2--meaning that it takes a lot more casts of a high-power Revenge Curse to kill something than it did in EO2.

Now, is it worth leveling up? In a standard run where you're using a Hexer as a disabler, no. If you're using your Hexer primarily as a debuffer, I guess Revenge Curse is something for them to do. Be very warned, though, that carting a low HP Hexer around is asking for trouble in literally every possible situation.
I'll be frank, my eyes glaze over at the mechanics for this. All I can really say is that this isn't EO2.

Blinding Curse

Attempts to inflict blind on one row of enemies. Has an 80% speed modifier at all levels.
Blind is the lowest on the ailment hierarchy for a fairly good reason, but it still has its uses. Not many enemies resist it, and inflicting it, assuming completely average dice rolls, effectively cuts enemy damage output by 66%. Blinding Curse has a significantly lower infnliction chance than Madness and Torpor Curse, for some stupid reason, but whatever.
There's quite a few fights where landing blind can win you a few good turns of actions. It's absolutely worth taking even if it isn't as absolute as the others.

Madness Curse / Torpor Curse

Attempts to inflict panic (Madness Curse) or sleep (Torpor Curse) on one row of enemies. Has an 80% speed modifier at all levels.
Panic is the second most useful of all the ailments, just behind fear, while sleep is useful for random encounters but is usually of dubious usefulness in boss fights.
Panic almost completely shuts down a target when inflicted. There still is the risk of a random attack tagging someone squishy, but it's way less dangerous than most active enemies. Sleep is good for single-hit burst setups, but that's about it, honestly.

Corrupt Curse

Attempts to inflict curse on one row of enemies. Has an 80% speed modifier at all levels.
lol curse
I absolutely hate you, curse. Damn you and damn your requirement to get nice shirts.

Stoning Curse

Attempts to petrify one enemy. Has an 80% speed modifier at all levels.
Single-target effectively-instant death. I guess for certain random encounters this could be useful?
It can work for random encounters, but it's also fairly expensive for something to spam on enemies given that it's single target. I mostly just use it for conditionals.

Relapse Curse

Reduces the chance of all enemies recovering from ailments and binds at the end of turns. Has an 80% speed modifier at all levels.
So a short bit about ailment/bind recovery: Basically, the LUC of the target that's trying to recover, the average of the opposing team's LUC, and the number of turns that the enemy has failed to recover from the disable are fed into a formula, and then that formula spits out a chance (from 0% to 80% for turns 1-3, and 100% on turn 4) for the target to recover from the disable. Relapse Curse basically subtracts from the chance between turns 1-3 of attempted recovery; after that, it gets overriden by the guaranteed recovery.

Given that disables can, at most, last for five turns, Relapse Curse is mostly a question of "how early can I cast this so that I get maximum value from it." Making a disable last for the full five turns is fairly unlikely, but incredibly useful, and if timed right, Relapse Curse can make it a reality. Ultimately, though, you're still mostly at the whims of RNG.

Cranial Curse / Abdomen Curse / Immobile Curse

Attempts to bind the head (Cranial Curse), arms (Abdomen Curse), or legs (Immobile Curse) of one enemy. Has an 80% speed modifier at all levels.
The binding Curses, due to being single-target, are mostly useful for FOEs or bosses. In random encounters, you're generally better off just using one of the ailment Curses.
These are pretty damn reliable on a wide variety of targets, and a great setup for Ecstasy or just plain lockdown.

Evil Eye

Attempts to inflict fear on one row of enemies. Has an 80% speed modifier at all levels.
You might be wondering "why is another ailment Curse at the very end of the tree, with a requirement of maxing out Curse Mastery?" That's because fear is a special ailment for Hexers, and Evil Eye actually has its own tree of special skills that require the ailment to work. Fear on its own kinda sucks--it's basically just paralysis--but the skills make it worth trying to inflict.
When you land fear with the proper skills that go with it, things fall down. This is Hexer's bread and butter for mid-lategame on targets that it can reliably stick to.

Luring Whisper

Can only be used in the Labyrinth. Increases the encounter rate for a set number of steps.
I don't know why this is under the Evil Eye tree. I also don't know why you'd ever want it.
If you're farming for Grimoire Stones via random encounters, it's vaguely applicable, I guess? It'll only save you a few seconds for poor SP investment.

Muting Word

Targets all enemies. If an enemy is afflicted with fear, they will do nothing for one turn. In addition, for one turn, all damage directed at the enemy will be amplified for one turn. Has priority at all levels.
Muting Word's not as generically useful as Suicide Word, but if you coordinate big burst damage with all your party members, the damage amp can result in some really serious hurt.
This is my favorite Hexer skill. I play parties with multiple damage dealers with multi-turn setups, so it lets me do some serious damage for a good few turns once my setups are in place.

Conflict Word

Targets all enemies. If an enemy is afflicted with fear, they use their turn to attack either one random enemy, or themself. Has priority at all levels.
Kind of a clunky and not-that-great way of giving Evil Eye Hexers some encounter-clearing capability.

Suicide Word

Targets one enemy. If that enemy is afflicted with fear, they will use their turn to attack themselves. Has priority at all levels.
The big skill of the Evil Eye tree. Not only does it guaranteed shut down an enemy's turn, it also makes them deal damage to themself. The damage can actually end up being fairly hefty, depending on the enemy's STR and especially its relation to their VIT.
The modifiers themselves on this are pretty huge. I haven't worked with this much myself, but it seems pretty damn strong, especially for EOU's relatively low modifiers.

Staggering Word

At the start of every fight, the user has a chance to attempt to stun all enemies, with an 80% base chance at all levels.
Waste of skill points.
This is way too situational to be worth it.