Swans of Bryn Argoll can be combined with Seismic Assault to convert every land into a draw-two
Also, we skip the cards with two names like modal-double face cards, transforming cards, and split cards like Aang, at the Crossroads/Aang, Destined Savior are not in contention
I'll try to come up with something fitting
No activated abilities of the target nonland permanent can be activated for as long as it remains tapped, even if those activated abilities' costs involve untapping that permanent
There are a lot of useful Rats you want to stick on the battlefield, and Swarmyard helps make your opponents require two removal spells if they ever want to take care of a Rat
And neither is his +1 to pump something (which includes indestructible as an option) or exiling after the next turn