Is Overlord of the Mistmoors legal in Standard, Modern, and Commander?

Overlord of the Mistmoors is legal in: Standard, Modern, Pioneer, Legacy, Vintage, Commander, Historic.

Overlord of the Mistmoors

Q: What type of card is Overlord of the Mistmoors?

Overlord of the Mistmoors is an Enchantment Creature — Avatar Horror. Its oracle text reads: "Impending 4—{2}{W}{W} (If you cast this spell for its impending cost, it enters with four time counters and isn't a creature until the last is removed. At the beginning of your end step, remove a time counter from it.) Whenever this permanent enters or attacks, create two 2/1 white Insect creature tokens with flying."

Enchantment Creature — Avatar Horror

Impending 4— (If you cast this spell for its impending cost, it enters with four time counters and isn't a creature until the last is removed. At the beginning of your end step, remove a time counter from it.)