PrivateinjectThis method is an unmaintainable mess and likely stems from us
never actually instantiating BattleScene via Phaser.Game correctly.
Furthermore, this also makes testing any form of Phaser-related infrastructure absolutely
infeasible, and must be revisited before a multi-scene breakup can be considered.
Initialize the given BattleScene and override various properties to avoid crashes with headless games.
The BattleScene to initialize
A Promise that resolves once the initialization process has completed.
Override the scene and stub out various properties to avoid crashes.