FLash nova is learned at 290. This skill level can be achieved at 79 with merits.
Does around the same damage as seraph strike. Flash when it lands last about as long as an unresisted flash.
Edit: seems that if the flash does land it can't be partially resisted. I haven't had it not land yet.
Edited, Jun 29th 2010 8:59pm by Laxedrane