Chalalalalalalassa
What a melodic name...
Acrobatics: Pretty okay ability, I used it from time to time.
Bleeding Strike: A 10 turn bleed at max tick damage (5% health) is huge against a boss, but also in the steam tunnels it was very valuable. I didn't bother one-handing Krimm, so Chalassa put this up on every lizardman in every fight, then joined Vaelis in single targeting. I think it was too easy to get max tick damage. I don't think I ever DIDN'T get it. Also it was elementary to the flashback quest. I used this and cycled defend/potions and let it plus the degen kill the guy.
Stealth Assault: I took this but I quickly got disappointed when I noticed that you lose the buff if you get forced into the front row... I'm pretty sure that happened. In theory it should be decent though.
Poison Dagger: Took it but it didn't see much use. Can't say much. Decent but probably wouldn't pick it again.
Meditate: Useful enough. Maybe not with Jariel around though.
Krimm
Rage: This is an awesome ability that gives her great resource management combined with Protect. I really like how Krimm tends to have "always some but never infinite" mana.
Kick: This is probably overpowered. There's tons of mobs who don't even care that they're in the back row and will continue fighting from there, penalized. And the ones who do care need to spend a turn moving back. On that note, it is my observation that while swapping places has a delay of 4, if you swap with another character they also incur that delay, so essentially this is an 8 delay skill that gives the enemy 4-8 delay and debuffs them. And those debuffs are extra great on a boss.
Protect: As mentioned, combines great with Rage, and the +attack is obviously nice for Chalassa. Krimm's first Protect was on Riley. It had a delay of 200 while I argued with her about it.
Adrenaline Rush: I thought this was gonna clear stagger the moment I used it, but it clears it on her next turn. This is probably for the best, although you might hate it if you eat an attack while staggered between your turns. Maybe it should just make her immune to stagger? It's awesome either way. Even if she's not as tanky as a ranger or Vaelis could be, she can clear the stagger she gets from guarding the back row, and that's valuable.
Finishing Blow: Like I said, too hard to hit the sweet spot. Fun though if you like to see ridiculous numbers.
One thing that should be mentioned is the very low delay of Adrenaline Rush and rather low of Rage, plus their low SP costs, which means Krimm can shake off her buffs/debuffs rather fast, for good or bad.
Riley
Slumber: Probably overpowered like Kick, so easy to get a semi-nasty debuff on a boss.
Mana Burn: I tried it but I think we're dealing with too small SP pools/too short battles in this act. At best it denies like 1-2 spells.
Ghost Form: A mighty good spell. My ranger sometimes received this and spammed Taunt/Defend etc etc, I think I reached 400 defense without even using a shield. It's really nice to throw this on someone who's getting pummeled anyway.
Energize: Oh boy mana battery spell. But I think it has the right balance; the gain is very slight and must be weighed against the cost of stalling a monster while regen kicks in. Maybe it's possible to practically heal the party to full using it and turtling hardcore but that was too boring even for me. Good spell though, it does more than just give mana and I didn't always think of it as downtime reduction, it could just be that extra oomph someone needed.
Nukes: I used them from time to time. More for the debuffs than the damage.
Rowinda
(more guesswork than experience)
Syphon Lyfe: Never used and probably never will. No scaling!
Dark Empathy: Approved.
Soulbound: Also approved.
Life Channel: I imagine this to be overpowered as hell. If you haven't tried it you might want to note that each party member receives 15% her health; they don't split it. I could see myself with a Rowinda just piling up health and using this repeatedly.
Anathema: I think the investment is too high for only a debuff. It could have a lower cost or delay. Compare it to druid nukes.
Nukes: Now these are row nukes worth taking. Not looking at any druids in particular.
Madness: The most famous spell she has apparently. I tried it against Yeldin but he didn't seem to want to go mad so I can't say much
Overall I like her high mana cost concept combined with her ability to regain mana.
Jariel
Oh boy may I never have to fight without him. He's a total gamechanger. Let's just say this will be about Vigorous Sonata more than his other abilities combined.
Vigorous Sonata: Let's skip straight to it. This spell is absolutely huge. If the maths aren't obvious to you, check this out. Our spells have static costs. No matter what you do, you can't spend more SP per turn than your biggest ability costs (unless you get mana burned or something). And that's assuming you always want to use that spell. Right, but our mana pools are NOT static. We can grow them by increasing will. They grow inevitably whenever we level up. The larger our mana pools, the smaller a % of them is removed when we use a spell. But this, this will always restore 10%. And for 10 turns and on the whole party, I would use it even if it was 5 turns and on one guy.
I fully expect that if it is kept this way, I can forget about SP regen altogether. And I might opt to not take several mana management abilities and suffer through until I get Jariel. Give everyone 15-20 will, but I was already doing that except for Krimm. It's pretty much use whatever you want to use while this song is up. Resource management goes out the window. Planning for the next battle? No longer needed.
Offensive chants: These are also quite powerful. The damage is pretty much symbolic, but slow on the whole enemy team for 5 turns? Gimme. Also they had good names.
Song of Purity: The second best part of this ability is what it does. The best part of it is that it doesn't interfere with Vigorous Sonata.
Lastly let's not forget to talk about how the act 1 characters' skills are working out in full party environments! A few I want to mention.
Bramble Coat: I took this when my ranger hit 12, and I didn't find an opportunity to try what I really wanted, but check this tactic for any high HP opponent. Spam Taunt. Receive Ghost Form. Use Bramble Coat. Chalassa or maybe Vaelis can put up a bleed. That guy is gonna lose 5% from hitting the ranger and 5% from the bleed, every turn. He's gonna be dead in 10 turns and the party can just bunker up meanwhile. I think BC and DoT's need to do less than 5% to a boss. BUT REMEMBER I RELY ON THAT FOR CHALASSA'S FLASHBACK
Taunt: Great with the improved mana situation in act 2 (larger pools + Riley). My ranger doesn't stand in the middle so when his aggro makes him the target of an ability that hits "target + sides" it only hits two people, not three.
Purification: Has really started shining! Especially against the assassin in the arena, but I've found many uses for it.
Nature's Touch: Yep, in full party environments it does pay off to have it.
If at first try it doesn't explode, it ain't Jack who wrote the code.