Against sion, Sion can surprise targets that are walking around Summoners Rift alone by waiting in a bush and using his Q to take them down. Avoid walking in areas where you know Sion has been so its harder for you to get caught out by him.

Kite and disengage is Sion’s biggest threat in a team fight. Try to keep him away from your team so he is unable to get a good Q knockup.

Avoid grouping and fighting in the jungle as it will allow Sion to either get a really good knockup with his Q or get a really good Ultimate R off. Group together, but do not stand on top of one another so he is unable to get a multi-person knockup.  Against sion, Sion can surprise the targets that walk around the Rift Invocation alone while waiting in a bush and using its Q to shoot them down. Avoid walking in areas where you know that Sion has been so much harder for you to get caught by him. Kite and disengagement is Sion is the biggest threat in a team fight. Try to keep him away from your team so that he is unable to get a good Q knockup. Avoid regrouping and fighting in the jungle as it will allow Sion to get a very good knockup with his Q or get a very good Ultimate Roff. Group together, but not stand on each other so he is unable to get a multi-person knockup.