If you've fought this, you know the deal; you spend more time running to something or away from something than you do getting any DPS time on boss. And if you're too slow to get up to add for interupt, you're done. If you're too slow to get away from his AoE, you're done. If you miss your rune, you're not done but you'll miss a significant DPS buff + free heal, which means you'll probably be done. It's stupid and the whole fight feels like it was designed to spite Rets (and probably DK's).