[Taqwus]

The Ark appears to bLast every relevant target with blindness, disease and -slight- damage. I suspect that it's "MR easily resists" or milder in strength as it's not hugely overwhelming, at least damage-wise.

Nethgul is pretty wacky; there's a set of spells it can cast, so it can Body Ethereal you, it can teleport you around the battlefield (eek!), it can Paralyze or Mind Burn as well, and it sometimes seems to try to paralyze -you- for some reason. It's on the unpredictable side, and is no longer the guaranteed 2x Mind Burn/turn.