User blog comment:RoznosicielCiast/OP stuff not that good as considered by everyone? Balance, countering, sticking to meta without thinking, Riot's fails/@comment-5291670-20130813021051/@comment-8506165-20130817113020

"Guess what, he was just a moderately better Sion"

lol.

The only similarities are innate sustain and the potential to use health for increased AA damage. And even the sustain's different because Sion's is a brief lifesteal increase on his ult, Aatrox has his on one of his basic abilities and it triggers every third attack.

They bring different things to a team - Sion has (arguably) better utility with a targeted stun and AoE heals on his ult's lifesteal effect, and more tankiness from his theoretically infinitely scaling health. Aatrox mostly just brings damage, but he brings more of it than Sion, and as the previous poster mentioned he's much less kiteable.