The 10 provided grids are Star Battle puzzles (as hinded at by the first grid). Solving these puzzles, then reading the lettered squares with stars in them will give you two disses from each of five different Epic Rap Battles From History, with one diss from each combatant.

These disses can be used to match the grids together. Matching the grids, then reading the letters in the star squares which were empty in the enemy's grid, with the grids sorted by episode date, and then by order of billing of the person doing the dissing yields the message CONTACT HQ TO SHOW US YOUR NEW RAP BATTLE. Teams which do so received the answer to this puzzle: SELF-DECLARED.

Answers to the star battle puzzles, with extracted letters circled, and in sorted order, follow below.