Yeah, he's got some good cc and a really good poke.If worse comes to worse. You can proc that Colossus and w shield for a massive shield that might save you and your adc. He can engage with his q, e and r, also and vice versa. The ult is nice for chasing down the adc or supp left behind. In my opinion, if Sion is played as supp correctly. He has one of the most decent chances to win bot lane with his quite aggressive kit. I usually max e so Sion can chunk health down as fast as possible, while wasting little amounts of mana compared to his q and w. Gank-ability is really good as well, if bot lane is dealt well and enemy mid is over extending. You can try to position your ult to hit the mid champ. I think Sion would make a solid supp champ, considering you start with
or
. This Relic shield allows you to kill minions and stack his w passive slowly for further health scaling without taking gold for yourself. Kinda like a health scaling thresh in a way.