I want to ask you guys for some inputs, should I release the characters one by one for wave 2 or release them all together?

(Some features for wave 2 will not be implemented fully until the entire wave 2 release as it is, but features or new things that are meant to release with wave 2 will be implemented with the first character release, this will include:

-New easter eggs
-New mechanics depending of the character
-Maybe new options?

Also, if I add the characters one by one, I could at least have time to prepare something for, not only the first anniversary of the game, but for Halloween as well.