Is Suspended Sentence legal in Standard, Modern, and Commander?

Suspended Sentence is legal in: Legacy, Vintage, Commander.

What type of card is Suspended Sentence?

Suspended Sentence is an Instant. Its oracle text reads: "Destroy target creature an opponent controls. That player loses 3 life. Exile Suspended Sentence with three time counters on it. Suspend 3—{1}{B} (Rather than cast this card from your hand, you may pay {1}{B} and exile it with three time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost.)"

Suspended Sentence

Instant

Destroy target creature an opponent controls. That player loses 3 life. Exile Suspended Sentence with three time counters on it.

Suspend 3— (Rather than cast this card from your hand, you may pay and exile it with three time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost.)