Cross class skills (For bard)

[Kroktar]

Blood for Blood(You gotta be ready to unclick this buff if the boss is going full AOE)
Invigorate(this is a MUST for Bosses even mass AoE trashes so you dont run out of TP or wasting 20% of your damage on songs)
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Second Wind(Also a must, this WILL save you tons of times in bosses)
Internal Release(This is gonna be one of your most used CD for DPS, because of the low CD time.)

The 5th its up to you, I would suggest Featherfoot when you are going into dungeons with a lot of trash (Keen Flurry its not that bad..but sometimes you die so fast so there is nothing to parry so evading 100% of the damage its better) but if you are going to a primal or boss exhausting i would say Mantra.

For soloing You can consider Feint or Haymaker(Sadly Haymaker its just a normal skill it cant be used off the GCD)
I would say Haymaker...Cuz...Damage