First post being updated. Sorry for the long absence, but this now conforms to what you mentioned Anitarf. Although, I do disagree on the fact that I should exclude the GroupEnumUnitsInArea library and just copy paste it inside the spell scope. That part, I did not do. I figured that people might find it handy, and some people may already have the library in their maps so I'll just be adding worthless lines of code.
EDIT: Updated. Hope all is well now.