Sure, here's an example of a single HTML file implementing a Battlegrounds game with JavaScript. It includes the selection of 5 characters, each with their own moves, abilities, and ultimates. Please note that this is just a simplified implementation for the purpose of this exercise.
Select Your Character:
Bald Hero
Hero Hunter
Menacing Cyborg
Deadly Ninja
Brutal Demon
In this example, there is a selection of five characters represented by pictograms. The player can click on a character to select it, which will activate the ultimate ability associated with that character. The selected character is visually highlighted with a border color change.
Please note that you would need to replace the image sources in the HTML code (`src="emozi_dog.png"`) with the appropriate paths to the actual pictogram images you want to use.