Here's my analysis of the best attackers out the Spirits book! The Spirits aren't the best damage dealers compared to some other books, so you likely won't be relying on many of them for that role.
First, let's take a look at the ranking of highest damage output for the strongest AoE attack of each monster:
- Uria's Pet
- Tempest
- General Uria
- Glitch
- Lux Aura
- Noctum
- Uriel
- Commander Alvid
- Uru
- Sylvannis
- Scryb
- Goldfield
- Lostyghost
- Singularis
- Totem
And now the ranking of highest damage output for single target attacks:
- Uria's Pet
- Sylvannis
- Tempest
- Commander Alvid
- General Uria
- Lostyghost
- Uru
- Lux Aura
- Noctum
- Glitch
- Uriel
- Singularis
- Goldfield
- Scryb
- Totem
Tier 1:
With nothing more than his base damage, Uria's Pet tops both lists. His attacks (without any modifications) deal WAY more damage than any other Spirit by far. With a single target skill that deals 85 Thunder damage, no other Spirit comes close. However, that's just about the only thing he does. One skill can daze a single opponent and his trait is the awesome "Tough". Unfortunately, to maximize his damage potential, he has to be paired with a support monster who can give him damage boost or double damage. Lastly, he's kind of a glass cannon; he deals big damage, but has extremely low life.
General Uria is in much the same circumstances as his pet, although he has more life. He deals heavy damage and is Tough, but not much else.
Tempest is one of the monsters in this game that can be a denier or an attacker. I like to load mine up with speed runes and let him stun and blind all my enemies, but he does have some hefty damage output as well. If you ran him with strength runes and paired him with another monster to boost his damage, he too can put a hurt on the enemy.
Glitch is a great overall monster. Like Tempest, I recommend using speed runes on Glitch. His Kill Switch ability corrupts a single target (same as possession) and glitches it, giving it double damage to use on its allies. Just be careful using this ability on a Hardened or Tough opponent, you might give them double damage without the corruption! He also can give a random negative effect to all enemies, drain some stamina, remove good effects from enemies, can heal himself, and is immune to possession.
Lux Aura, like most light monsters, is immune to blind. But the real draw with her is her ability to give an ally (or herself) double damage and precision. She can also give her whole team precision, most of their energy, and remove all debuffs in one move. After she's boosted, she can deal 60 Light damage to a single target or 40 Light damage to the whole enemy team.
Tier 2:
Commander Alvid doesn't have the highest damage output, but she deals all sorts of negative status effects to the entire enemy team: burn, poison, and removing energy (if you keep a skills group 1 ability). Most monsters won't last more than a few turns after Alvid has hit them. If you can boost her damage, she does have a decent single target attack that can decimate an enemy. I personally recommend running her with speed runes, so you can get those status effects attached sooner.
If Uru's skills or base stats were a bit better, he could be an amazing attacker. He has an ability to give damage boost to all his allies, but that's the only thing it does. It almost feels like a wasted turn. So many others can boost damage and do other things. He also has an AoE stun ability and is another you can build as a denier or attacker.
Honorable Mentions:
Singularis has no high damage output, but he has one ability that gives instant to death to all enemies after 4 turns. I find most battles end before then, but it's very helpful if you're up against a tank like Ouros. He can also slow an enemy and give himself haste. But I find monkeying with in-battle speeds always makes things weird.
Sylvannis has a very high damage single target attack, can poison all enemies, and heal his allies. There are so many monsters who can do more damage than him, but he's worth mentioning when compared to other Spirits.
Others:
Goldfield is an easy legendary to rank up as he is breedable, but he's a supportive monster, not a damage dealer himself. Uriel has the almost unique ability to resurrect fallen allies. He can also heal, blind, and daze, but he's not known for dealing damage. Noctum and Scryb are more supporters/deniers. Lostyghost doesn't amount to much of anything. And Totem was... an interesting experiment on SP's part.