In Touhou 10: Mountain of Faith, MarisaB (Marisa Kirisame's B shot type) has a known damage exploit that allows players to deal significantly higher damage than intended under certain conditions. Here’s how you can execute this exploit:

Charge Attacks: MarisaB's damage exploit primarily revolves around her charge attacks. The charge attack is activated by holding the shot button until the charge bar fills up.

Damage Calculation: The exploit involves a bug in the game's damage calculation system when using charged attacks. Essentially, the damage multiplier for charged shots can stack under certain circumstances, leading to much higher damage output than normal.

Execution:

Begin by familiarizing yourself with MarisaB's charge attack mechanics. Practice charging and releasing shots to understand the timing and effectiveness.
During gameplay, when engaging in boss fights or against tough enemies, use MarisaB's charge attack strategically.
The exact trigger for the exploit can vary based on the game version and specific conditions, but generally, it involves timing the charge release or possibly chaining charges in quick succession.
Testing and Practice: To effectively utilize this exploit, spend time testing different scenarios in the game. Practice charging and releasing shots against various enemies to observe the damage output and identify when the exploit triggers.

Community Resources: Given the popularity of Touhou games, there are often forums, guides, and community discussions where players share strategies and specifics about such exploits. These resources can provide additional insights and help you refine your technique.

Remember, exploiting game mechanics like this can significantly alter your gameplay experience. Some players enjoy discovering and utilizing such tricks to challenge themselves or achieve high scores, while others prefer a more straightforward approach. Use this knowledge responsibly and in accordance with your gaming preferences.