Merlin Jungle

1/X/Square: Frostbolt is a good burst ability, comparable to Kuku 1. It slows and does a significant amount of damage. This is a good solo engagement skill or a good finisher. Eclipse or Radiate are both good for clearing a camp or a lane when you are in those stances.

2/A/Cross: Blizzard and Dragonfire are very good for clearing a camp quickly at first level. In addition, they are both very good zoning tools, and both apply an effect: Blizzard slows and Dragonfire reduces protections. Vortex is useful for dragging enemies back towards you in a chase to finish them off.

3/B/Circle: This is a Blink.

4/Y/Triangle: This is Merlin's Stance Change. I have 2 things to say about this:

First, This ability also does AOE damage around you, and has an effect based on your CURRENT STANCE. (Fire: burn, Ice: slow, Arcane: knockup)

Second, You can choose your stance! By default it cycles Arcane (1) > Fire (2) > Ice (3) HOWEVER, after you use the ability, you can press 1(X/Square) to change to Arcane, 2(A/Cross) to change to Fire, and 3(B/Circle) to change to Ice. If you press the option for the stance you are in, it will instead change to the default order.

I find it useful (especially in the early game) to bounce between his ice and fire stance. Ice is a good engaging stance due to the slow, followed by fire, dropping a Dragons Breath to reduce protections and finishing off with Radiate or another ult > ice stance.