Make it "that you don't control" and I'm behind you as a nice way to justify a cost increase to wrath. Seems too easy to game in a token deck otherwise. ("Oh, drat; guess I'll have to wipe the board and gain40 life; good luck wiping that out before my horde is ready again")

What? Wrath is the cheapest possible for its effect; all variant-Wraths are 5 or often 6 mana (or otherwise harder to cast like Supreme Verdict). You want this to be a one-sided wrath, aka Plague Wind?

This is a fine expansion variation on Wrath; if anything I might expect it to be 6 mana a la Phyrexian Rebirth. But 5 is fine.

No no; I just want the life-gain half to be one-sided. (So you usually gain half as much)

If this were the only wrath in an environment; I wouldn't mind too much that it costs more than the minimum; because the upside is quite nice. Indeed; I was thinking it a bit too nice.

Upcosting is not an option :)

Well, personally, I think gaining life for only one side of the board isn't an option. Wouldn't it be frustrating if you were already playing a token deck, and, when you cast this card, you couldn't gain life for all your dead tokens? That doesn't seem fair. You also couldn't build around this card, which means this card would only ever be better than Wrath as a silver bullet answer, as opposed to a quasi-combo piece. Why you no let me combo?

You might be right about the power level Vitenka... I'm not sure if 5 or 6 is more fair on this card. But I think the hyper-token scenario you're imagining is too optimistic. If my opponent has 3 creatures, and I have 10 1/1 soldier tokens, I should probably attack. Casting this spell in that scenario would often be a mistake.

I don't think it matters a lot, any of the options would be a nice wrath spell. But when I first saw it, I assumed it would be "each player gains 1 life for each creature they controlled destroyed this way".

Keep in kind that this is for a custom cube set, so the power level is supposed to be high. The idea behind this card (for which I cannot claim original credit) was to provide a Wrath variant that would actually be playable in a typical cube control deck. In this situation, the control player will usually not have a substantial number of creatures in play, so if any sort of nerfing were to be done, it would need to be something like "Each player gains 1 life for each creature destroyed this way that an opponent controlled."