I master my first skill BALEFUL STRIKE couse it gives me 1 ap per minion kill and 4 ap per champ kill,and you use that skill for harrasing and dmg.The second skill is used mostly for farming and vision,it is hard to land it without your stun.The stun is the most important skill couse you need to get enemy at the corner to stun him.Enemies with spell shields, like Banshee's Veil or Morgana's Black Shield, will not be affected by the stun from Event Horizon when walking through it and will have immunity if they pass through it again.Blinks are unaffected by Event Horizon. For example, Kassadin can use Riftwalk to get out of the Event Horizon without getting stunned.AND dashes are sometimes affected by Event Horizon. Event Horizon checks for units to stun every .25 seconds[3]. In between these checks, it is possible for a dash such as Spinning Slash to make it through unaffected. Note that since it is possible that a check occurs while the dashing unit is going through, they will sometimes be stunned at their destination.And if you are fighting ap carry you ult will destriy him,couse your ult deals 120% OF YOUR AP AND 80% OF ENEMY AP AS DMG