Bloodfang
The Immortal Tiger
Tremor is cool but because of being all summons and only full meter ambushes he's not what Scorpion needs. Metallic is my favorite for the low/overhead ball and the lava blasts personally but the Crystal also has great utility in giving him ways to eat projectiles while possibly spearing on recovery. The summons though bring it down imo. Scorpion needs ways to open up people while being able to attack/defend himself. And while Tremor, the earth ninja, definitely has some solid dirt it's not enough to pull Scorpion out of the hole he's been buried in.