Stormbringer

You’ll start a noncombat showdown. (Hostile Takeover’s reminder text is a little misleading in this regard—you have to have some kind of showdown before you can conquer.) This ruling applies any time you have a unit at a battlefield when your opponent still controls that battlefield, but doesn’t have any units there. (Yes, that can happen. Hostile Takeover and Stormbringer are the easiest ways to do it.)

There’s a gap in the current rules that leaves this situation without an obvious outcome. We plan to address that gap in the next regular rules update. The issue is surprisingly complex, and we’re not 100% sure what the answer will be when we’re done.

In the meantime, though, we believe starting a noncombat showdown is the least disruptive way to handle this scenario. If you need really precise timing: assume that your opponent loses control of the battlefield in the same cleanup that begins the showdown, even though ordinarily control is “frozen” once the battlefield becomes contested.

Temporal Portal

出典：Riftbound Spiritforged FAQ