If someone can shed some light on this spell Radiance. I have been messing around with it on lower level mobs to see the point of it.. and quite frankly I just don't see the point to ever use this unless I am doing something wrong?...

spell requires 1000 TP to use, I found the only way I seem to build TP (and not that much of it) is to use my spirit dart (which is on a 10 sec cd..) I just don't see myself waiting 10 sec to build barely any TP and to what? get maybe 2mp back (because thats what I got when I used it) Also as CON soloing / doing levels.. I want to kill as soon as possible without standing around.. is this spell one of the ones that are useless for CON? I am new so just wondering about it since I like to know all my spells and what they do.

Thanks.