This card has no downside, as its only effect is destroying all creatures without any strings attached
Sorcery Common Johan Grenier null/null NOT LEGAL Standard NOT LEGAL Future NOT LEGAL Historic NOT LEGAL Timeless NOT LEGAL Gladiator NOT LEGAL Pioneer NOT LEGAL Explorer LEGAL Modern LEGAL Legacy NOT LEGAL Pauper LEGAL Vintage NOT LEGAL Penny LEGAL Commander LEGAL Oathbreaker NOT LEGAL Standardbrawl NOT LEGAL Brawl NOT LEGAL Alchemy LEGAL Pauper Commander LEGAL Duel NOT LEGAL Oldschool NOT LEGAL Premodern LEGAL Predh Create two 1/1 red Goblin creature tokens
And of course Mirkwood Bats is the nastiest of all, bleeding each opponent on both your token creation AND sacrifice
(As a side note, it's useful to know that this is actually the earliest possible time in a turn that any player can do anything
In late July of 2021, I finally had an opportunity to explore these questions when a friend visited with me, and we played these two decks I put together just for this experimental purpose
When Court of Vantress becomes a copy of a permanent, it's neither entering nor leaving the battlefield