Forum:Catalyst Field

Hi. I was wondering about a scenario regarding the effect of Catalyst Field to "target 1 card your opponent controls; banish 1 Gemini monster you control, that is treated as an Effect Monster, and has gain it's effects, until my opponent's End Phase, and if you do, destroy that card."

If my opponent (after resolution of this effect) destroys my field spell, would my monster stay banished? I would think it wouldn't since the effect already resolved which states it will return during my opponent's end phase, but I want to make sure. I know that banishing is part of the effect, and not a cost, which is great for me since if it were a cost, they could chain and destroy it upon activation to make me lose my monster, but this specific scenario after resolution has me unsure.