This is something of a unique battle; firstly, Alias cannot be harmed by magical attacks so don't bother with them on him, and secondly, he cannot be hurt physically when he hides behind either the barrels or crates.
Equip Koudleka with a pistol of some sorts and James with a weapon of your choosing. Edward as usual, will attack physically.
Target the barrels and crates with a spell or have Edward hit them, so that Alias has to waste a turn moving for cover. Alias will attack only from a distance with a six-shot pistol which will deal a fair amount of damage, so have James heal when needed.
When the barriers are gone, Alias will be vulnerable to physical attacks, so attack him with everything you've got, just remeberering to heal if your HP gets too low.
| Barrels | Black Cat | Brute | Chikon | Sucker | Crates | Demonic Bead | Explode Corpse | Eyeball | Face | Ghoul | Giant | Giant Roach|
Hand of Glory | Headless Corpse | Corpse Hound | Inverse | Jester | Sham | Mars | Minotauros
Nobleman's Spirit | Possessed Armor | Possessed Chair | Possessed Shelf | Possessed Table | Pricktail | Puppet | Raven | Shadow | Skeleton
Spectre | Tamacoss | Vine | Watcher | Wight
| Werewolf | Giant Plant | Seeker Trio | Mummy Bride | Doppelgänger Koudelka | Doppelgänger Edward | Doppelgänger James|
Jailer | Mad Fly | Dark Young | Alias | Chimera | Gargoyle | Gug | Valna and Vigna | Charlotte's Wrath | Scapegoat | Apostle | Patrick's Vine
Elaine | Elaine (Final Form)