Is it worth?
Maybe in later levels since it scales with int?
If your fireball deals about 1k damage, the debuff will hit for about 250 or so. If you’re going as a linker, it’s worth taking to get a hit using flare.
Doesn’t flare work on anything standing on Flame Ground?
Flying enemies.
That said, no on the attribute.
The biggest problem is that it adds 8 seconds to Fireball’s cooldown, and the added damage is hardly enough to justifies that sacrifice.