This will be a Royal Rumble contested under standard rules. It starts with two combatants in the ring, with a new man entering every 90 seconds, and the only way to eliminate an opponent is to send them over the rope and have both their feet touch the ground.
Other than agreeing to the rules of the match, everyone is in character.
Here is the order of entry
1. Godzilla (Assume he's the size of the IRL suits)
2. Batman
3. Shaq
4. Aaron Carter
5. Abraham Lincoln
6. Optimus Prime
7. Jackie Chan
8. Indianna Jones
9. A care bear
10. Chuck Norris
11. Gandalf the Grey
12. Gandalf the White
13. Monty Python and the Holy Grail's Black Knight
14. Benito Mussolini
15. The Blue Meanie
16. Cowboy Curtis
17. Jambie the Genie
18. Robocop
19. The Terminator
20. Captain Kirk
21. Darth Vader
22. Lo-Pan
23. Superman
24. Every single Power Ranger
25. Bill S. Preston
26. Theodore Logan
27. Spock
28. The Rock
29. Doc Ock
30. Hulk Hogan
31. Mr. Rogers