Oooooh... eenteresting.

Means you can't be throwing around any sacc effects; and WILL be tapped out on your opponents turn, but in the meantime you'll have an incredibly efficient creature for a couple of turns.

I like the idea.

This is not an uncommon, though. It's probably a mythic rare.

Lol, maybe. I thought that "uncommon" is fitting because if the opponents has more than one blocking creature, it does lightly more than nothing. Is rarity considered on this specific set?

No, rarity doesn't really matter here other than as a gauge of your assessment of what effects belong at what rarity. I suggest rare or mythic rare because effects that transfer control of a turn haven't been done below that rarity before.

Taking control of players is a mythic ability.

OK, mythicized!

But it's a mythic downside. I agree, it maybe should be shown off on a mythic card; I'm not sure 'efficient one-drop' is crazy enough for it.

Cool card!

This is on the border between rare and mythic. Desecration Demon was rare, but Abyssal Persecutor was mythic. It's moderately rare for a cheap creature to be mythic, but not unknown: most recently Soulfire Grand Master and Warden of the First Tree, but also Dark Confidant, Lighthouse Chronologist and a few other levelers, Sage of Hours, plus Voice of Resurgence for cash-cow reasons.

This does look somewhat better than Vexing Devil. It's probably a bit too easy to just play all your spells in first main, tap out so your kill spells can't be used on your stuff, and beat down.