Is this possible ?

hm..just wondering if this is possible

Let's say a unit attacks an enemy unit with demonhunter's metamorphisis' attack and the green ball splits into 4 and attacks nearby units. Is it possible ? :/ If, it is. Care to share how to ?

It's very possible. You'd have to use some triggers, but it shouldn't be too hard. I'd help ya more, but I have a really bad headache, and am trying to work on my own map at the moment.