Sion not trash anymore!
I've been playing a lot of sion lately and many people may think hes just a garbage champ when hes exactly the opposite. Most people just try to build straight life steal and ad on him which will not work. My usual build is ravenous hydra statick shiv infinity edge phantom dancer mobility boots and a randuins/spirit vissage. There is not really a need to build excessive life steal on Sion since his ult gives him 100 percent life steal at lvl3. Building crit strike on Sion is AMAZING since if you crit for say 800 damage you will gain back 800 life with his ultimate not to mention the attackspeed boost.

This is what my finished build usually looks like