AI Fighters can be used as substitutes for almost every Tower Of Time challenge. To use them, simply toggle on the "AI Fighter" option after selecting a character, but before entering a battle. Using an AI Fighter will earn you the exact same rewards as a standard fighter. All you need to do is press continue between fights. For most battles using AI Fighters, put most points in the "Combo" and "Reversal" stats. To change AI Fighter settings, go to "Kustomize" and select a character. Then, choose any "Kustom Loadout" and go to the AI Fighter tab. All loadouts can be customized with AI Fighter settings - you do not need to create a new loadout. The best AI Fighters are Noob Saibot against anyone, and Skarlet against fast rushing characters and powerful zoning. Some bosses and hard battles cannot be completed with just the Combo and Reversal stats. If your AI Fighter is losing, try switching tactics. Select a "zoner", or a long-range character that is good at using projectiles and other abilities. Skarlet is a powerful zoner - equip projectile skills to her loadout, and boost the "Zoning" and "Runaway" stats to 30. Additionally, hearts are one of the rarest currencies in the game. To get hearts, you need to kill opponents with a fatality or brutality. You only get one per fight, so it can take awhile to get 250 - which is required to open a Shao Kahn chest. To easily grind hearts, enter the Klassic Endless Tower and use an AI Fighter. They will continuously fight, using finishers, and climb the ladder until they are defeated. You will get lots of hearts using this method -- without having to do much of anything.