Ultimatum is pretty much a quick recovery, as a War I rarely even bother with it flash....maybe because I know how my skilsl work and know how to balance TP. Also you are aware if you use an item like Max potion while pulling,or certain abilities, it triggers you to start at top enmity right? If you have a healer who cast before hand just stay a bit in front and be ready to aoe. It's simple. If this is still to hard use DRK or even PLD.