Make Wraith spawn in other modes than Mixed

[SgtBriar]

Give wraith an 20-30% chance of occurring in the next round if the last round had a high death toll in anything but nuke.

Kinda like how doing the solarium wrong creates a disaster round.

Like someone is very unhappy that they got murdered, or the dangerously effective traitor is reincarnated as something truly evil.

This could be nice but I feel like this would encourage rampages for additional antag chances