User blog comment:SirAston/URF and the LoL Engine - A To-Do List/@comment-8919271-20140402193057

Double damage duo Spirit Fire?

nope

Double the   Dark Passage, double the lantern, double the shield

nope, shields only refresh

Can Yorick summon the same type of Ghoul twice?

nope, summoning new ones kills previous ones

Ravenous Flock will disable because it's mana cost is constantly rising, and when mana cost is greater than your total mana, it gets disabled. Doesn't apply to Anivia or Mao because their mana costs are constant, though I think that Mao's ult does turn off after coupla minutes.