Fascinating. Heartbeat of Spring, only for colourless mana, but working on elves and artifacts too.

­Furystoke Giant + Aggravated Assault + 4 other creatures. Hmm... and some way to wash the mana, I suppose. Works on the turn you play the giant, too, so that's cute.

Of course, that's overkill (though, it will kill everyone in multiplayer all at once). But you can get a similar effect with Kyren Negotiations. Can't think of a replacement for Aggravated Assault... I'm thinking that's the real offender. You can probably do something with Intruder Alarm, but Intruder alarm is the answer to, like, 1,000 other combo decks. I try to avoid using it for that reason.

Also, Staff of Domination goes crazy with this... it roughly just loses the tap ability. Have two of this enchantment out, and you have infinite mana. SoD is much too old to worry about in that way... but does this break with Clock of Omens? I wonder...

The trigger says taps for mana, not just taps. Otherwise Seeker of Skybreak would start to do its best imitation of the GEICO pig, and I don't think we need to hear that.