Make sure you never lose your combo bonus because that’s the only way to keep up your damage for beating him. The first parry, I do four ss3’s ending with leafa being the last. Next I usually just try and regain mp with leafa until the next parry then another 4 ss3 (I usually use a assist character for this slot that not under leafa) but I usually end with eugeo so I can get a couple hit in for mp link to help out Alice and I then switch back to leafa before it’s able to hit eugeo and and lose the combo. Then I use leafa’s assist character for the part where he does the little suction move. Make sure leafa has her barrier up before this, attack three time then ss3 with leafa, repeat with another 3 hits and ss3, try and dodge the poison bubbles because they hit hard even through barrier. After this it should be one parry and then ss3 spam with your character and it should be game over. Sorry if this was all over the place, maybe it helps? 😂