Big-Wig Riftbreaker

Reach, Trample
Whenever Big-Wig Riftbreaker or another Gatekeeper enters the
battlefield under your control you may have it
fight target Rift you don't control.
Whenever a Rift dies gain 2 Mist counters and
Mystify that Rift, if you cast it from exile it
becomes a Gatekeeper(it is not a Rift).
It has been some time since I have gotten to make an example of your kind. I am going to make this quick...
and painful.