Bluescreen Blue Light Help

Oh, boy, that's tricky....

Can't go into specific step by step, but let's talk some strategies to approach this...

Remember you can stack keyers. You might have to use multiple keyers on narrower ranges. So, instead of trying to do everything with one key and fighting that spill on your face, you can key most of the blue, add a second (or third) key to try and get the rest of the screen. Multiple keyers is a typical technique for hair.

Remember you can use multiple LAYERS. Maybe on the bottom layer you can get a good key on your body but have holes in your face. Maybe drop a second layer on top, just try to key your face and reverse that key to bring it back.

Remember Set Matte. You don't have to directly use your keyed layer. You can try taking it to its own comp to key. Then maybe some color grade/correction effects can be used to boost contrast and color on the video to get a cleaner key. This Comp would become a Set Matte source for an alpha matte in your main comp. In your matte comp you can still use multiple keys and layers. Like a contrast boost should kill the spill on the hoodie, to key that easily, then another layer for the face.

You might just have to roto the face.

If all else fails, can you re-shoot?

These are AE tutorials, but show the basic concept of multiple keys and layers to isolate details. Should be helpful.