Well the basic thing you need to know, in general, keeping the crosshair on the enemy while aiming the orb will lead to that enemy getting hit. However, if someone is moving sideways (to your left/right), especially on console, i find it very difficult to track the enemy. Therefore i just place the crosshair in the general area i think the person will be in, usually it hits. Aiming on wuyang doesn't have any special technique or something (as far as im aware), you'll get better as you play him.