Flee and leave him to his fate

It takes more effort than you thought, but after a second of hesitation, you manage to turn around and run into the forest. All you hear is an explosion, an angry hiss, and the **** scream of your mentor. You feel a mental pain but you keep running. Your own morality marks you as a coward. And a traitor. But this is not the time for shame or guilt. It is time to survive and use your advantage to take the monster down. If you don't do it, Tocar's sacrifice would be for nothing.

You run until you are out of breath. You are now somewhere in the forest. But you can't care about your orientation now. You need a deep breath and a plan. While your heartbeat slowly gets back to normal, you listen into the forest. There are still no birds nor other animals. They probably got scared by you running around. It takes a while until you hear the breaking of branches heavy steps in the distance. The chimera is done with Tocar and is after you now.

You need to think. The chimera is partly wolf, so it most likely follows you scent with it's advanced nose. It is injured from the fight with Tocar and unlike you, it is running without a break, It must be angry, exhausted an distracted now. You are currently at a small ceiling. The floor is plain and you should have a chance to defeat the monster if you wait here. This would be risky, but the chimera is faster and more enduring than you. Continuing to run away is not an option.

But there is one more thing you could do. You could use the anger of the chimera as a distraction and lure her into a trap. A magic circle written on the ground that activates when somebody steps into it. It's complicated, but you did this before in several lessons. Enchanted weapons work basically the same way. They only need magic ore or crystals to work without connection to a mage. You don't have enough time to prepare for both. You need to decide for one option now.