Is River's Grasp legal in Standard, Modern, and Commander?

River's Grasp is legal in: Modern, Legacy, Vintage, Commander.

What type of card is River's Grasp?

River's Grasp is a Sorcery. Its oracle text reads: "If {U} was spent to cast this spell, return up to one target creature to its owner's hand. If {B} was spent to cast this spell, target player reveals their hand, you choose a nonland card from it, then that player discards that card. (Do both if {U}{B} was spent.)"

River's Grasp

Sorcery

If was spent to cast this spell, return up to one target creature to its owner's hand. If was spent to cast this spell, target player reveals their hand, you choose a nonland card from it, then that player discards that card. (Do both if was spent.)