Create some dudes! This was the other obvious application of the Top Swap mechanic for me, creating creature tokens. This'd be in a set that wants frequent creature token generation as a theme, and this card helps you consistently have that.

I feel like the mechanic of Top Swap is elegant enough to include additional mechanics, so here's Kicker. You can make a 1/1, and later you can make two 1/1s if you need the extra one.

This does perfectly gum up boards, which might be too much. Every turn you can make a 1/1 and filter away, which as long as you have cards in hand to bottom to Top Swap's ability you can always have blocks. They're as unimpressive as blockers as possible, at least.