RTF is a global modification that replaces all towns in the game.

In my opinion, the Undead tier list should be as follows:

Level 1: Skeleton (Melee). Skeleton Warrior, Skeleton Destroyer.

Level 2: Spider, Poison Spider, Dark Spider. (Ranged attacker, when attacking an enemy, it applies "Plague" for 1 turn) (Large creature)

Level 3: Death Knight, Dark Knight, Ash Knight (Small creature, casts Weakness when attacking an enemy)

Level 4: Ghosts, Spirits, Banshees. (Flying, small creature, applies Weakness when attacking).

Level 5: Mummies, High Mummies, Chosen Mummies. (Ranged spellcaster, can apply Blind, raise the dead, and Curse)

Level 6: Namtaru Mother, Fate Weaver, Reaper of Fates. (Ranged attacker, shoots a poisonous cloud)

Level 7: Bone Dragons, Black Dragons, Phantom Dragons. (Flying, large creature)