These kinds of threads always require context. I haven't finished the game. (Most of the time, I find I most enjoy talking about a game while I'm playing it, so this is sort of a necessary evil.) I'm playing on veteran. At this point, I've worked my way up all the skill trees to the top. I've started branching my characters into trees I didn't start them in to grab the bonuses cross-class bonuses. I'd like to discuss which abilities seem good and which don't. (I haven't used all abilities yet. Those I've italicized are ones I haven't personally used yet.)
Best
Fast Feint (Combat T2) 1en: Haste and Bless self for 4-5 turns is extremely useful before Battle Frenzy. Still efficient in smaller fights afterward.
Battle Frenzy (Support T4) 2en: Haste and Bless everyone for nine turns using only two energy is very efficient. (On a support w/ stacked blessing bonuses.)
Inspiring Cry (Support T1) 1en: Efficient way to bless everyone until you get to T4. You will also buy this on all PCs to stack blessings later on.
Haven's Command (Royal) pas: +8 damage (at level 9) if standing within six spaces of princess? Ultra efficient.
Good
Steelskin (Combat T2) pas: Reduce the likelihood of a plethora of negative effects passively. Very efficient.
Magery (Magic T1) pas: 20% bonus to healing, blessing and curses. Must-have on your main support character.
Raw Power (Magic T3) pas: increases energy 1/5lv. Energy is life. A must have for support and mage PCs.
Call Bones (Magic T2) 1en: summon a skeleton. He's not too strong, but he'll eat two or three hits. In the early game, this is worth two or three heals. Efficient. Useless later.
Build Construct (Magic T4) 2en: Provides a reasonably tough summon that can inflict statuses and hold choke-points, giving your PCs a chance to dakka with bows and arrows.
Hide in Shadow (Support T1) pas: Good to reduce aggro on support and mage so you can stack bonuses via robes.
Haste (Support T3) pas: 1/4 of the haste spell effect passively is very efficient.
Healing Wave (Support T3) 1en: Heal everyone for two energy. Use after a fight where the support is still at full energy.
Mediocre
Hardiness (Combat T3) pas: 10%/lv health bonus. Would be absurdly efficient if it worked as advertised, but my combat PCs only have +10 health compared to the PCs without this ability.
Brutal Blow (Combat T1) 1en: 25% damage bonus and bleeding. Can be helpful in difficult fights with big baddies.
Shock (Magic T1) 1en: "strong" damage, but it barely seems to do any more than a regular attack with a wand.
Weakness (Magic T2) 1en: AOE weaken. Can be useful against some crowds, but very unreliable when you actually need it.
Time Warp (Magic T3) 2en: AOE slow. Unreliable when most needed. 2en cost is stiff.
Speed (Support T2) 1en: 12 turns of haste on one target sounds good. But it's only 3.8 net turns (over the next 12 turns), in exchange for one turn now. Inefficient.
Healing (Support T1) 1en: Healing is not very efficient in this game. Can be good to top up someone when you're about to get energy restored and you're already full.
Curing (Support T2) 1en: I've only needed to cast this three or four times so far in this play-through. Normally best to let the DOT tick out.
Restoring Rain (Support T4) 2en: Might be good except I spent all this tier's points on Battle Frenzy, and filling in Magic tiers is more efficient than getting this ability.
Disruption (Support T3) 1en: Enemies don't usually buff, and even if they do, Haste and Healing Wave are very good.
Bad
All combat abilities not mentioned above (T1-T4) 1-2en: Combat abilities are too unreliable, considering many of the big bads have a high chance to resist the statuses you would otherwise inflict.
Terror (Magic T1) 1en: Single target CC is useless when it's so unreliable against big bads.
Icy Wave (Magic T2) 2en: Too expensive, seems to get evaded a lot, doesn't really do that much damage.
Poison Rain (Magic T3) 2en: Too expensive, and resisted by many classes of enemies.
Teleport (Support T2) 1en: I've never felt like I'd obtain a significant advantage from teleporting, except in battles I was going to lose anyway.
Silence (Support T4) 2en: I mean, I haven't tried it, but I'm guessing it doesn't work on big baddies given the pattern of other curses, which means it's useless. Even if not, Battle Frenzy!
Haven's Might (Royal) 3en: Same effect as Battle Frenzy, but costs one more energy. Entirely useless.
Haven's Mercy (Royal) 3en: Heal and cure nearby allies. Other cures suck, so I'm assuming this one does too. Considering casting costs, damage would have to be well balanced for this to be efficient.
Undecided
Shockwave, Fireball (Magic T4) 2en, 3en: Casting costs steep, other direct damage spells seem inefficient, so I haven't tried these.
Looking back at my feelings for all the abilities, a few main themes stand out.
For CC to be and debuffs to be useful, they need to be reliable. Abilities that don't work on big bads are kinda silly. Gradual immunity should be implemented (e.g. can't stun more often than once per four turns, slow has chance to fail on second application, etc.)
Healing is so bad that it is only useful if the energy would otherwise be wasted. I understand it was meant to be nerfed but this seems like too much.
Blessing and haste are extremely efficient. I'm not sure the game would be playable without them.
Bows and arrows are very strong. I kite most non-boss trash encounters. It's still fun, but I'm not sure it would be if this continues to be the pattern.
Support bonuses (+15 evasion, +10% speed) are better than magic bonuses (+3 en +1 magic damage). Both are far, far better than combat bonuses, which are very bad (+6hp, +1 physical damage).
Everything in the bad and mediocre categories could stand to be buffed. I say buffed because it seems like the content is balanced around heavy use of the good and best abilities. It's challenging despite using those and carefully stewarding energy and flasks.
If this thread proves to yield an interesting discussion (and maybe even if it doesn't), I will also post my thoughts on augments and runes. Spoiler: like abilities, there are only a few that are good. Most are very inefficient.
