^ Well, sometimes it will be a waste for the boss's skill if u do like that. I think u can use the periodic event that count unit within range of the boss, then base on the number of unit, u order the boss to use the spell. For example: If the number is 1, order it to use Storm Bolt (since that is a single target spell), if the number is 2, order it to use Thunder Clap (an AOE skill), if Thunder Clap is on cooldown, order it to use Storm Bolt on a random unit within range. That's my ideas. (dont have WE to write the triggers, sorry)