Solution: The Magic Match
Answer: TRIWIZARD TOURNAMENT

Written by Joman522, with assistance from betaveros

The solution can be viewed here: https://drive.google.com/file/d/1ic7rhWgWfI_l-8gBn_HMAmiShgNxOom6/view

Now, the surviving players read their letters in red-green-blue order.

Following the instructions results in the letters spelling out the answer, TRIWIZARD TOURNAMENT.