Multiple abilities in 1.

I'm trying to figure out a way to create abilities that build internal charges that can be linked to secondary or tertiary effects. The best way I could explain this is with a video:

A swordsman from League of Legends

"In this video, the blue swordsman (Yasuo from league of legends), has a thrusting attack. If he uses the attack, and hits a target, he gains a charge of steel tempest. If he uses it again, and hits a target, before the internal timer decays to 0, he gains a second stack of steel tempest. If he uses this thrust attack again, the attack changes to a new projectile style attack with new properties and consumes the charges of steel tempest."

I've seen battle symphony, but I'm not sure how far this could go in it. Anyone that can point me in the right direction, I will be much in your debt. Thank you in advance. :)

You could use the damage formula for the first attack to manipulate a variable and also check it in order to modify the damage output based on it. If it's need to be a different attack, you can try the variable manipulation + one of yanfly's scripts that allows you to chain skills

You could use a "dummy" skill that has a common event that manipulates a variable and then uses a force action event based on that variable to use the "real" skill.