White gets taxing and red gets rituals, so red/white gets Mana Drain, right?

o_O

Well, I'm not sure we can say that white has Rethink. But I'm willing to believe that it could have Remand...

Could get even sillier if you Remand-ish your own spell just to charge it up and make it more powerful next turn.

White does get Mana Tithe and a few other similar cards, though.

A more realistic Remand in white would probably be putting the spell on top of its controller's library and giving them the mana back.

Mana Tithe argues for white Force Spikes in the same way that Healing Leaves argues for green damage prevention. I'm not saying I wouldn't be cool with it. Just that it's a tentative shelf to build things on.

Planar Chaos is certainly not sensible precedent. But there's also Lapse of Certainty, Chancellor of the Annex, Frontline Medic, ... hmm, I thought there were a couple of others. But it is an area white dabbles in from time to time.

Although it seems like most of the white examples are focussed on making spells more expensive, rather than countering them by surprise. Maybe there's an on-board version of this?

And there are some Planar Chaos (but not color-shifted) cards that counter things that target you or your stuff, and some old cards that counter white's enemies and things it can destroy. White's really quarternary in counters. I could make this an enchantment that sacs.