How???

How can someone sustain SO well, solo?

I was playing with a WAR in Pharo hard, on the final boss, we wiped somehow, EXCEPT him. He finished the boss from about 40% remaining HP. We cheered him on as his life would drop down and as it looked like he was gonna die, he’d spring back to life again, and again...and again..We all complimented him and as quick as he came, he just left with an “Lol I’m a Warrior” like that means he can’t be killed?

Then I was in Great Grubal with a PLD and I was healing on SCH. It took me until the third boss before I realized, I wasn’t healing him...Sure I had Selene, but I she was on auto, and I was focused PURELY on DPS..Then we got to the third fight and I realized that his HP seemed to never drop more than 20% and even then it would instantly refill between Selene and whatever he was doing.

Now I can sustain a TINY bit on DRK, between Potions, and my CD’s and life steal abilities, but not quite like that WAR, and I sure as heck have to try harder than the PLD did to mitigate damage.

What am I missing?