Tentacles are an immense source of power. Don't fight without them.
Spirits inherit their target's current health. If making a
is your goal, try whittling your opponent's health down a bit first to make killing the spirit easier.
Leap of Faith is best used to follow-up a strong engage or when being engaged upon. Be careful about being the first one into a fight.
Killing Tentacles whenever possible will make it much easier to win a fight against Illaoi.
When your spirit gets pulled out, fight back if you can. Dealing damage to Illaoi reduces the spirit's duration.
Avoid grouping up for Leap of Faith to reduce the number of Tentacles available to Illaoi.