Information about classes is messy as fuck and difficult to parse (people "explain" by assuming you already know what they're talking about)

Here's my experience on the Valk so far.

Resource generation.
  • SP is your resource.
  • Shift+Space will cast "Vow of Trust" a channel that will (basically) fill your SP at a cost of stamina.
    Do this after combat (I sometimes do it in combat)
  • Guard (Q) will put you in a defensive stance.
    You will block attacks taking ZERO damage, this will generate SP
  • Breath of Elion (Shift+E) heals a small amount of health and generates moderate SP
  • Forward Slash (forward+LMB) is your best generator, though I rely on guard, breath of Elion and Vow most of the time.

Combos don't seem to be important for leveling the Valk. I may be wrong :P
I use these on the hotbar.
Here's my approach to resource spending: (in no particular order)
  • Celestial Spear (backwards+E) grants crit, moderate damage
  • Shield Throw (backwards+Q) aoe, 12s cd for stun, can be used during cd (resets timer & doesn't stun)
  • Sword of Judgement (backwards+RMB) main damage, 3 hit string last hit deals bonus damage.
  • Shield Counter (RMB during Guard) light damage + stun.
  • Divine Power (Shift+F) moderate AOE
  • Severing Light (LMB+RMB) light aoe that restores minor hp.

Special mentions
  • Heaven's Echo (Shift+Q) "taunt" that grants extra defence to you and accuracy to nearby allies.
  • Punishment (E) Heavy damage CC. I use it on annoying casters, but it's mainly for PvP

  • Shield Chase: shift + direction during guard.
  • Righteous Charge (forward+F)
  • Sideways Slash (left or right+LMB) useful to avoid big hits, but useless to spam
  • Evasion (shift+direction) Basic combat roll to avoid shit, I use it fairly often :P

Now, I'm absolutely certain that at endgame when you have all skills unlocked correctly performing combos will be mandatory for best performance, but I think this breakdown works very well for levelling (so far)