The Master of Souls

This is a strategy guide on how to defeat the bosses in Act I. Please note that there is around 20 something bosses in total, I'm only going to add the bosses and not the boss fights where you fight a bunch of really hard monsters, or where you are supposed to lose. Also, I will only go into detail on the major bosses so that I don't bore you. There are some spoilers toward the bottom, so be careful :)
Chapter I:
Hydra:
Health: 205
Mana: 100
Attack: 12
Skills: Minor Frost, Minor Flare, Minor Shock
Strategy: Have Pete use Minor Poison if he is above level 6, otherwise have him use the Trapped Dagger to poison the Hydra. Have Aeon use Fire Shield on both him and Pete.

General Lourk (1st and 2nd times):
Health: 405, 1000
Mana: 0
Attack: 26, 35
Skills: None
Strategy: Aeon should have at least Tectonic Slap or Quake, use these earth spells both times to deal lots of damage. Have Pete poison or confuse him. Do NOT use ice spells.

Dark Faerie Queen:
Health: 750
Mana: 500
Attack: 25
Skills: Trick, Negative 450, Toxic Burst, Spoken Curse
Strategy: Have Aeon use Magic Shield on both him and Pete, then use his most powerful earth spell (or Biome III), have Pete Confuse or Poison her and then attack.

White Tiger:
Health: 1500
Mana: 1300
Attack: 28
Skills: Blizzard Touch, Negative 450, Frost Wave
Strategy: Have Aeon use the Scroll of Heat Wave you won from the Dark Faerie Queen to deal a ton of damage, and then use Disaster Ultima. Have Pete Poison him, and use any items when needed.

Yelean:
Health: 750
Mana: 1300
Attack: 22
Skills: Shockwave, Toxic Burst, Demon Wave, Parasitic Drain, Maelstrom
Strategy: Have Aeon use Disaster Ultima, and have Pete Poison him or use items.

Chapter II:

Stranger (2nd fight, you are supposed to lose the first):
Health: 750
Mana: 1300
Attack: 22
Skills: Shockwave, Toxic Burst, Demon Wave, Torment, Maelstrom.
Strategy: For the first half of the second fight, lose and then choose to have Lidya help you. Have Daniel attack and have Lidya use Poison Arrow (You should have the poison oil by now).

Kenny (2nd fight, you are supposed to lose the first):
Health: 80
Mana: 0
Attack: 14
Skills: Slashes of Yvain
Strategy: Have Daniel use slashes of Yvain every turn until his health drops too low, then heal and attack Kenny after the guards die.

Moth:
Warning! DO NOT FIGHT UNTIL YOU HAVE OBTAINED THE VAMPIRE TOTEM!
Health: 760
Mana: 600
Attack: 20
Skills: Minor Swarm, Drain
Strategy: Have Daniel attack, or if you have learned Purge of Galahad use that. You can have Lidya try to use Posion Arrow, but the Moth has resistance to Poison.

Serqqa:
Health: 565
Mana: 400
Attack: 30
Skills: Scorpion Sting, Minor Swarm, Venemous Bite, Summon Scorpion
Strategy: I recommend that you have James for this fight, and that you use his Winds of War trick. Either way, have Lidya use Fire Arrow to destroy the scorpions quickly.

Cobra:
Health: 1060
Mana: 300
Attack: 35
Skills: Toxic Burst, Venemous Bite
Strategy: If you have James, have him use Sandstorm or at least Winds of War. Have Lidya use Fire Arrow.

Captain:
Health: 1500
Mana: 500
Attack: 36
Skills: Assasinate, Courage, Call to Arms
Strategy: If you have James, he should use Wildfire to attack the entire enemy party, and Lidya should use Poison Arrow to poison the enemies as they appear.

Spider Queen:
Health: 1150
Mana: 500
Attack: 36
Skills: Spawn Spider, Spawn Colony, Toxic Burst, Venemous Bite
Strategy: If Daniel has the Sword of Ages equiped, have him use Dance of Kay, or even Purge of Galahad when the spiders are summoned to destroy them. WARNING: The spiders heal and revive! Have Lidya use Fire Arrow on the Spider Queen, NOT Poison Arrow.

Slug Tyrant:
Health: 1645
Mana: 700
Attack: 34
Skills: Spawn Slime, Slather, Paralyzing Slime, Madness
Strategy: Equip Daniel with Daneed for this fight, and have him attack the slimes as they appear. Have Lidya use Fire Arrow on the Slug Tyrant throughout the fight.

Delia (1st and 2nd fights):
Health: 750, 1800
Mana: 1500
Attack: 21
Skills:
1st: Toxic Burst, Demon Wave, Shockwave, Maelstrom, Madness
2nd: Toxic Burst, Demon Wave, Shockwave, Maelstrom, Curse of Fear
Strategy:
1st: Have Daniel attack with whatever his strongest weapon is, and have Lidya use Fire Arrow. Make sure that who ever is dealing less damage uses items to heal, Delia can deal a lot of damage.
2nd: Have Daniel attack with his strongest weapon, and have Lidya attack with the Tsunami Bow, or with Fire Arrow. Make sure you have lots of Blessed Infusions, Tea Leaves, and Healing Salves for this fight! You will need them.

Chapter III:

Hazal:
Health: 400
Mana: 400
Attack: 14
Skills: Radiation Beam, Chlorine, Phosgene, Toxic Burst
Strategy: I recommend using the option of having Madame Cura for this fight, her skills can counter Hazal's, and she can heal Poison. Have Thrusen either memorize Phosgene if you don't have Madame Cura, and use it against her, or have him hit her with Suffocate.

Damien:
Health: 400
Mana: 400
Attack: 15
Skills: Charm, Amnesia, Puppet Mastery
Strategy: Make sure you have the Amulet of Psych equiped, otherwise you will instantly become confused and kill yourself! Use Cackle to defeat him, or if you have found a spell that works better for you, you can use that. Nex Caedem Vomica isn't reliable in boss fights because it only hits bosses 20% of the time, but some people will get lucky.

Atlas:
Health: 400
Mana: 200
Attack: 21
Skills: Body Slam
Strategy: Use Caedem Wave, Charm or Nex Caedem Vomica to easily defeat Atlas.

Corra:
Health: 360
Mana: 330
Attack: 15
Skills: Deadly Embrace, Future Sight
Strategy: Use Caedem Wave or Nex Caedem Vomica to quickly destroy Corra.

Ealliot:
Health: 600
Mana: 400
Attack: 16
Skills: Cow Curse, Warp
Strategy: Have the Amulet of Alteration equiped, it is the only way to not be turned into a cow by his curse! Try to memorize Warp, it will come in handy later, but then use Caedem Wave to beat him.

Black Hole:
Health: 850
Mana: 700
Attack: 17
Skills: Demon Wave, Curse of Fear
Strategy: If you don't already have it, memorize Curse of Fear, it is very useful later. Then use Warp or Decimate to beat the Black Hole in a few turns.

Neko:
Health: 1050
Mana: 900
Attack: 23
Skills: Meteor Shower, Temporal Disturbance
Strategy: It isn't possible to kill Neko with Nex Caedem Vomica, so your best bet is to use Warp (Which I told you, you should have learned earlier) it is the only spell that works well against him.

Axel and (Mesmerized) Artys:
Health: 1300, 1050
Mana: 1500, 1100
Attack: 21, 13
Skills:
Axel: Toxic Burst, Demon Wave, Shockwave, Maelstrom, Tridom Bombardment
Artys: Cacophony of Insanity, Healing Chord, Curse of Fear
Strategy: Alternate between two spells every other turn: Use Corruption the first turn to render Axel unable to do anything, then strike them both with Decimate. Keep doing that every turn and you'll probably win. If Artys deals to much damage, you can replace using Decimate with healing, but ALWAYS use Corruption on Axel.

Chapter IV:

Dark Knight:
Health: 195
Mana: 50
Attack: 12
Skills: Warden Vortex, Power Hungry
Strategy: Attack with the Iron Hammer, or use Holy Scrolls if you found any. Have Christina heal when needed.

Vampress:
Health: 395
Mana: 250
Attack: 20
Skills: Deadly Embrace, Vampiric Drain
Strategy: Equip Christina with the Holy Symbol, and attack the Vampress and her Vampire with that. Or, if you have a Holy Scroll use that. As always, heal if you take too much damage. You should kill the Vampress first; she is more powerful and has a one hit KO spell (Deadly Embrace).

Kekale:
Health: 100,000
Mana: 1500
Attack: 21
Skills: Toxic Burst, Demon Wave, Shockwave, Maelstrom, Glorious Demise.
Strategy: Don't even try to attack Kekale, he rendered you weaponless in the cutscene. The only way to win this is to let him die from his poisoning. He will take damage every turn, and it shouldn't take more than 10 or 11 turns for him to die from this. The only thing that Christina can do is heal from the massive damage he deals each turn.

Chapter V:

Priestess:
Health: 3200
Mana: 800
Attack: 26
Skills: Peace, Glorious Demise, Holy Flash, Recall, Judgement Day
Strategy: You can use any of the six characters for this, so go ahead and pick you favorites! You have to use Aeon, so have him use Disaster Ultima each turn to take care of the Angels she will summon. If you use Pete, have him attack, or Poison or Confuse the Angels. If he is in the Spy Guild, have him use Diplomacy. If you use Daniel, just have him attack with the weapons bought in Tar' Jahri. If you use Lidya, have her attack with the Palm Bow or have her use Poison Arrow on the Angels. If you use Thrusen, have him use Curse of Fear on the Priestess, and Decimate when the Angels appear. If you use Christina, have her attack the Priestess or Angels, unless any damage is taken then have her heal, revive, or remove status conditions.

You are supposed to lose this last battle, but I'll throw in the stats for fun. These are the same stats that will be used in Master of Souls: Act III for this particular boss.

Master of Souls:
Health: 80,000
Mana: 10,000
Attack: 150
Skills: Fire Bomb, Demon's Gift, Seams of Darkness, Decimate, Soul Blight
Strategy: See how long you can survive!

Well, I hope this helped people! And if it did, I'll do another one for Act II. Go enjoy the game folks!