My initial understanding was that the hero could be either agility OR intelligence. It seems the OP has been changed. I very much want to make my entry Intelligence. Can this be changed back please?
Melto, this wording for the skill interaction is more clear, I believe. Use this:
Interaction between skills means specifically that two or more of the hero's abilities effect the casting or use of the other skills when cast alongside each other. Both skills must have separate, individual issues as well. For example, Skill Q causes X effect, Skill W causes Y effect. When Skill Q is used directly after Skill W, Y effect is somehow modified by X effect.