PRO TIP: DO NOT TRY TO HEAVY MELEE AFTER CHARGING SOMEONE UNTIL YOUR CHARGE IS LEVEL 2 - the duration is not long enough and players have time to parry this melee, instead use light melees until that point.
Skill order/AP Explanation You start with charge and focus on maxxing it as fast as you can to have the most uptime on it as the cooldown is really long, next you go for siphon life as it will help you partially with killing targets with a bit of extra damage, then your ult and finally infernal.
Early Game If your lane is difficult, put a point into infernal resilience for added health regen to try and stay alive. Grab at least lifestrike from melee items after finished then look at mid game