Regulus' mines are grenades
Regulus' mines are now awesome to play with, full stop (before lack of scaling kills off the use of any ability). However, this only comes into practice when the opponent is bunched up and/or standing still. Because of the way running creeps spread out, they're actually not very effective as mines, since it's rare for the enemy to set all off in a short time (Demigods) or set it off so that many creeps die (Creeps) although early on, you can fire Mines into the enemy lines for some nasty, nasty damage. I suggest that they are reworked so that they detonate instantly (right now there is a lag time) but the triggering radius is essentially smaller (or detonation radius increased). Most of the things I could come up with to make them worth it against running creeps made them horrifically OP against Demigods, so you may need to rethink them.