Build and Runes
Try to burst down Sion’s shield – this will prevent the shield from dealing any damage, cutting his damage down in half.
After Sion has died, have someone on your time stun him when he goes berserk otherwise he will chase down your team.
Reposition after killing him to get away from his Glory from Death.
Player made terrain will interrupt his ultimate. This makes champions such as Trundle, Jarvan, Azir, and Anivia very valuable to have on your team against a Sion.