The indestructible could cause you to lose harmony for that turn -- awkward.

RE: "simple creature" wording. I feel like it would be best if it was kept as close to the original term (creature with no abilities) as possible, for ease of adoption. "Abilitiless" is kind of a bitch to read, but I feel like it would be perfectly understandable once a player learns what "ability" means in terms of MTG. Alternatively, "pure" can be used instead of "simple". Both are adequately fine, though it's going to be tougher to sell people on differentiating "creature with no inherent abilities" and "creature with no abilities as it exists currently".

It would be ideal if we could just write “vanilla creature,” but much like “mill” it’s a game term that doesn’t make sense in universe. Abilitiless is kind of mechanical, unlike other recent wording updates like dies and create. Pure feels too white associated, we think. Other terms that have been considered are Primal, primitive, clean, and plain.

As far as whether it counts A Grizzly Bears with Lightning Greaves, that’s very much still up in the air. One concern is that to a lot of newer players that are familiar with the term vanilla, it might still seem like it should count as a vanilla creature. If we were WotC we could spend some money doing a study to see how people tended to think it works and make that the way we go, but alas we do not. Leaning more towards this direction right now because it’s just mechanically nicer to be able to use combat tricks on your guys without possibly screwing up al your synergies, and there turned out to not be that much space playing around with “loses all abilities” style effects (especially in green).

—CF