1 he has every night kills, our games with vigs are almost always a limited number of shots with sks being unlimited
2his kill is a poison type. This type of kill helps to protect and mislead as the victim dies on a different night.
3 he has a rival. Mario has declined to answer if he has a rival, you havent commented. I can only assume that rival isnt an overarcing flavour that you all have, but a distinct character oriented rival. In mafia most rival relationships involve sks and killing types.
His fluff also almost makes it seem like it only works on one person, since it uses the pronoun "his" in the role description.