With the new balance mechanics they are shifting the game away from needing 1 of roughly 10 mercs in order to be successful. If you had played the last 4-5 events you would have a stable of incredibly high stat multi hitting epics that didn't need buffs to kill. I have no reason to believe this will change in the future. Plus, you can purchase pretty much any lethal merc in game now for 1 res or less.