Is Shredder, Unrelenting legal in Standard, Modern, and Commander?

Shredder, Unrelenting is legal in: Standard, Modern, Pioneer, Legacy, Vintage, Commander, Historic.

Shredder, Unrelenting

Q: What type of card is Shredder, Unrelenting?

Shredder, Unrelenting is a Legendary Creature — Human Ninja. Its oracle text reads: "Sneak {3}{B} (You may cast this spell for {3}{B} if you also return an unblocked attacker you control to hand during the declare blockers step. He enters tapped and attacking.) Deathtouch Whenever Shredder enters or attacks, another target creature you control gains deathtouch until end of turn."

Legendary Creature — Human Ninja

Sneak (You may cast this spell for if you also return an unblocked attacker you control to hand during the declare blockers step. He enters tapped and attacking.)