Heizou, Deceiver of Voice

Flying, Ward {x}—X is equal to the number
of Cultist creatures other players control.
If this card would be cast from exile it has
Convoke.
Whenever a Cultist creature another player
controls dies, surveil 1 and Heizou, Deceiver
of Voice gains a +1/+1 counter.
"Come closer... Just follow..."