Arianna, tips for you:
- Rotate on his distance so he will not jump to knock you down
- Spam "2" (single target) + LMB + F and/or some combos if you have
- Buy 25 AP gem in marketplace worth 10g and put it on your weapon (usable up to end game)
- If you are on low hp, press E -> 6 (i put hotkey 6 for potion) -> Tab (instant 30% hp)
Good luck!