In BG2, the Slayer form :
https://baldursgate.fandom.com/wiki/Slayer_Form- Gives full immunity vs Finger of Death(OHK in 2E), Imprisonment, Charm, Confusion, Level drain, Panic , Sleep
- Immunity to arrows, throwing axes and other missile weapons up to +2
- Set AC to -4, in 5E equivalent that is +4 AC over full plate armor
- Set THAC0 to ZERO ie - to hit full plate armor the slayer needs to roll ZERO,
- Set STR/DEX to 25 - That is literally GODlike in AD&D. which gives +14 damage and to carry 1600 kg of stuff
- 4 Attacks per round and 8 with improved haste
- All saving throws are set to 2, ie - only rolling 1 the slayer fails a save
- 40% MR(this is hard to translate into 5e)
- 100 hp, and is 100 hp in a game where even dragons and adamantite golems rarely get 3 digit hp.
Now, in BG3, in therms of damage and resistance, the slayer form is worthless.
If Larian don't wanan something as powerful as Slayer in BG2, I would suggest to make it at least as good as 5e tenser transformation. That spell in 5e :
http://dnd5e.wikidot.com/spell:tensers-transformation
- You gain 50 temporary hit points. If any of these remain when the spell ends, they are lost.
- You have advantage on attack rolls that you make with simple and martial weapons.
- When you hit a target with a weapon attack, that target takes an extra 2d12 force damage.
- You have proficiency with all armor, shields, simple weapons, and martial weapons.
- You have proficiency in Strength and Constitution saving throws.
- You can attack twice, instead of once, when you take the Attack action on your turn. You ignore this benefit if you already have a feature, like Extra Attack, that gives you extra attacks.
I would only change "attack rolls that you make with simple and martial weapons." to "unarmed attacks" and the "2d12 force damage" to d12 necrotic damage + d12 cold damage as it fits more a Bhaalspawn than pure force damage.
