If this card leaves the field: You can add 1 "Mewtwo" monster from your Deck to your hand
These are all definitely worth opening from a booster pack now and throughout the set's time in Standard
Anaba Ancestor Anaba Spirit Crafter Boros Battleshaper Boros Reckoner Boros Strike-Captain Etherium-Horn Sorcerer Felhide Spiritbinder Firesong and Sunspeaker Glint-Horn Buccaneer Gornog, the Red Reaper Karplusan Minotaur Kazuul Warlord Lord of Shatterskull Pass Maelstrom Artisan Minotaur, ROXXON CEO Neheb, Dreadhorde Champion Neheb, the Worthy Oracle of Bones Rageblood Shaman Sandstorm Crasher Sethron, Hurloon General Tahngarth, First Mate Tahngarth, Talruum Hero
Special Summon it in Defense Position
But that small boost is precisely why its so great
Spells and Trap negate effects can only be used during your own turn, but being able to negate your opponent's Quick-Play Spells and Traps is strong