Hello :3
Sure, first if you mean that the character is not in the scene, then that's because I create the characters directly from the events, but if you mean the objects don't have sprites, then something is wrong in your project, try downloading it again, and if it keeps happening please provide a screenshot of how it looks like, so I can understand more.
For the combos:
Open the project → Game scene → Events → Player 1 mechanics → Controls, or the abilities (energy ball/small energy balls...etc.), all events are commented, I explained how everything works in their just make sure to read the comments.
Tip:
The objects' folder "Characters" contain The skins of the picked character from (ChooseYourCharacter) scene, and contains the actual controlled objects (Pink objects), when the scene starts, we create the Pink objects that we control, and we create the skins on top of that objects and make it follow the pink object.
Tip2:
Game scene → Spawning players, read these event's comments, it will help you understand how we are spawning the players skins and controlled objects.
Hope this helps :)