I beat both my first go round (Though each took several wipes). Honestly, just keep trying. Also, explain the boss mechanics because people are going to be new in DF and both of those bosses are pretty unforgiving if you don't know what to do. Also, make sure your melee DPS is using LB2 on the bosses. Especially Garuda. Using it can be the difference between wiping in phase one and advancing to phase two.