Damage sion dies instanstly so hes worthless

The passive revive doesn't matter for engage, and OF COURSE HE IS GOOD for his wombo combo ult+Q+W+E initiate. That is what a tank is SUPPOSED to be good at, CC and utility. He is not supposed to be a melee ADC like old Sion, and that is why people think he is bad, they won't let go of the old play pattern they used to know. After his passive triggers, he has already locked down/killed at least half the enemy team with his AOE nukes, so being a little kite able only matters if your team isn't there to clean up (which would mean you engaged a whole team... alone... what?).