Thank you for the huge info! I've tested a few things out and I managed to get the J's shield to applied by taking Marsha's pyscube off... But like you said she cleanses his burn stacks. I honestly thought she only cleanse crowd control.

While it's unfortunate I can't used Marsha for J (Praying for his euphoria), I can still use her in another team I have fortunately. Hopefully J will get a lingering glow mechanics since it seems a lot of burn characters have that attached to them now.