let's say I get Terrak in on a mon that isnt Fini, Buzz, or Hippo.
You clearly are switching to either Buzz or Hippo.
If you switch to Hippo:
I SD again, I'm now +3 and OHKO you. You do not OHKO Terrak and have nothing to RKill so you proceed to be 6-0d. If you switch Hippo at when I'm +3 something else is dying, then Hippo will nearly be dying once you intim again.

If you switch into Buzzwole: You get straight OHKOd, then the Hippo situation happens.

so ya.