(snip) Are there any monster abilities you find completely arbitrary? You know, the type of ability that just seems tacked on, and may even hurt the verisimilitude?
The tanar'ri. Why are they immune to electricity? Also, in that they're immune and also their primary foes, the baatezu, don't have any resistance at all, why don't they make more use of electrical-based attacks?
Then again, I think the tanar'ri in particular, and fiends in general, are grab-bags of random legacy abilities with no thought as to why they are possessed.
