If you're fighting a singular male lion on it's own... They're not brave without their pack and they're way more 'bark' than bite. It's just like a black bear, be as big and loud as you can. Do not ever run, this triggers an instinctual urge to chase. Alone in the face of a fight it's not sure it can win, the Lion will want to run though. That will just buy you time, closing the gap and actually winning the fight will depend on circumstances, but you can get the upper hand in a lot of ways.
Whatever happens, be thankful you're not fighting a Tiger.
rookie vampire mistake. Just summon in a swarm of wolves and mist-form away whenever the lion gets close. Maybe shoot some of the spectators some beguiling eyes and throw them at the lions too. Once its too full to keep moving, then deliver the coup de grace.
They have sensitive noses but they can't be stopped mid charge and likely won't be deterred by peeing in their face. Maintaining eye contact will make them slightly more hesitant but also angry.
They swipe harder and faster than Mike Tyson in his prime, but if it's a show lion it might be suffering from lifelong narcotics addiction so at least you've got that going for you. The bite force is enough to sever your limbs so never let it grab you.
TLDR Stay away but don't run, try to hit it's nose but never get near its face.
What are the rules? Are you allowed weapons of any sort?
Is it like gladiator style combat or are you allowed ranged weaponry?
This is pretty vague, and I'm fairly sure the community rules say that when posting questions about lions you need to be very specific otherwise you're what is known as a "dingus."