The skills you will need: Life steal, fast reflexes
Recommended extra skills: Riposte, sneaky attack and if no sigils bandage wounds
Highly recommended items: Camo charm and life steal rings (a couple of restores in case you need them but I only use 2-3 a lix so its not expensive)
I have personally used this way to level and got 11% a lix.
Also you MUST SUPERCOMBO or this will not work and u wont heal enough because the supercombo boosts your attack speed, running speed, defence, attack, armor, and much more but its all needed.
You will need alot of dex like I have 300+ dex with reflexes on a supercombo will boost your defence to 2000+ and provide around 600+ armor.
When you start your supercombo only kill 1*-3* mobs because 4* specials do too much damage to recover from before killing it. When I did this my defence at 2600 allowed me to dodge 70-80% of the autos. The 20-30% when you get hit use life steal to recover your health. 44/35 lifesteal with 300 dex can give you up too 950 health when cast.
MAX XP:
If you can duel device with a level 60+ mage that has maxed lure of assassins and fire have it help you for up to 15% xp a combo.
INSANE XP:
If you duel device with a mage and have 1-2 friends out of group damaging after you get the target lock will get you possibly over 20% a combo!
I hope this is of use to any of you

P.S. I thought of this once but didn't dare to try it in case it was expensive on the restore part but when I meant to set off a balloon I accidentally hit a super-combo lol
P.S. #2 DO NOT try this on a regular lix because it does not work it will hurt your wallet!