Regulus and his mines.
In every game I've played that has Regulus as an opponent, what seems to happen is thus, they toss their mines and a second later they detonate, usually inflicting anything up to 1,500 points of damage instantly and from a very safe distance. All it usually takes after that is a snipe and the Regulus player can probably run in, take 50% damage while finishing you off with regular attacks and then scapering. I would have thought the mines would be a defensive ability, not an offensive ability. I'm not going to rage or beg for their damaged to be nerfed but I would genuinely love to see the range of them dropped by half or two thirds.