Not future-proof. Not even Mistform Ultimus-proof.

My technique was to introduce the game term "diversity" and define it as "the number of creature types among creatures you control or seven whichever is lower". That works fine

This is not a white effect anyway. The EV is above the size of bonus you'd get as white, so this should be green.

Yeah; you'd need to explicitly limit it to creatures with a small number of typers.

It's very white flavour; though. Feels like a thing that should be doable.

Well, you could find a mechanically white card text to go with that flavor easily.

You don't just give green a hard counter spell, just because the flavor fits.

But the flavour of "Lots of creature types get together to make an army more powerful than an army of just one type" is a white concept. Whole greater than its parts and all that jazz.

So something like this should be possible. I agree not this though. Maybe the threshold variant - "As long as you control three or more creature types, creatures you control have +3/+3" or something? (Even +3 is pushing it though)

> But the flavour of "Lots of creature types get together to make an army more powerful than an army of just one type" is a white concept. Whole greater than its parts and all that jazz.

So make it:

> "Creatures you control get +1/+1 until end of turn.
If there are four or more creature types among creatures you control, they get +2/+2 instead."

Or anything similar that's fine in white. Or grant first strike upon the threshold.

Also possible: > "Any number of target creatures get +2/+2 and lifelink until end of turn. You can't target a creature this way that shares a creature type with another creature."

Or:

> "For each creature type, choose up to one creature you control not yet chosen this way. The chosen creatures get +2/+2 until end of turn."

etc.

None of the wordings is a Vitalizing Wind nor do any of them require to name-drop changeling in an attempt to make the mechanic useless when it comes to providing creature type diversity.

"As long as you don't control a creature of every type..."? It's admittedly un-pretty, but it at least solves Mistform Ultimus and some future problems.

Funny that it can get shut off with a Shields of Velis Vel. ;p Which I guess brings up another problem card for the card as it reads right now. Shields doesn't give creatures Changleing. Neither does Wings of Velis Vel, Blades of Velis Vel, Amoeboid Changeling, Mirror Entity, and now Volatile Claws. Why don't these cards grant the keyword? I haven't the foggiest. It's like they were setting themselves up for trouble in the future.

They don't grant the keyword due to the way layers work.

Adding/Removing types is processed before adding/removing keywords/text, so a granted keyword that alters types actually won't alter types.

Devoid has the same problem since changing colors also comes early.