Wow. This is eye-popping, and I was convinced it was utterly broken for quite a while, until the full ramifications of the sorcery clause dawned on me. It's no good at all at foiling most removal, because it can't stop a Day of Judgment at all; sorcery-speed burn is on a different turn to it, instant-speed burn can be done in response to the activation... about the only removal this does help against is Rebuke. It's obviously great to stop your attackers dying in combat, but Dolmen Gate did that to all your guys for 2 mana.

It's still a rather nice card, especially for aggressive decks, but nowhere near as broken as it seemed at first; many decks won't get much use out of it at all. Nicely balanced, in other words.

Wow, never heard of that gate; that seems immensely broken to me. But protecting one creature a turn? That feels fine. It promotes interaction and making interesting choices.

It certainly can stop a Day of Judgment, if it happens to be yours. I get the impression that this card would create a lot of turn 6 blow-outs, after activating two of them and wiping the board.

I'm considering making it legendary and letting it tap for a white mana. That way, you wouldn't be able to drop 4 of them with some crop rotations and then use a board wipe, but they'd also be more useful at least for having color.

Besides, the ability does feel very white to me, personally.