^ I think a simpler way, rather than detailing all the combo strings, would be to have the attacks generate stacks of an effect that modify them.
For example, lets say your WAR weaponskills all generate 1 stack of Rage.

Heavy Strike:
Deals damage with a potency of 100.
Additional effect: Upgrades to Fracture with 1 stack of Rage.
Fracture:
Deals damage with a potency of 140.
Additional effect: Upgrades to Storms Eye with 2 stacks of Rage.
Storms Eye:
Deals damage with a potency of 150. Consumes all Rage stacks.
Additional effect: Recovers HP equal to 20% of damage dealt.