Repost from my post in the general bug thread:
Several bugs with Wages of Sin:
First of all, several players in that scenario (and possibly in other scenarios) use their world spells in the first turn - for example, the Elohim and the Ljosalfar do (Actually, I think the Elohim did something similar in Barbarian Assault). I would guess that the AI uses its world spells partly depending on whether it's on war with other civilizations - and this scenario and others have the "Always War" option enabled. In that case, the conditions for using these world spells really have to change.
(...)
Thirdly, I've tried the scenario several times already and always quit in frustration after I was visited in turn 10 or so by a basically unkillable unit: Basium. (And if I actually managed to kill him, I wouldn't be happy, either, because this seriously hurts the Mercurians...). Hyborem starts with UnitAI_Defense or something like that while Basium had UnitAI_Attack - perhaps that's the problem? In any case, Basium mustn't be allowed to attack that soon personally - either he kills (or at least harasses) the player at a very early point in the game, or he dies that soon. Neither option is particularly satisfying.
Hopefully, this bug report was helpful in some way.