How do you get level 100 in one battle?

Reaching level 100 in a single battle typically requires the use of experience-boosting items or mechanics, such as a rare item that grants massive experience or a specific battle against high-level opponents. In some games, utilizing experience multipliers, like a "Lucky Egg" or similar, can significantly increase the experience gained. Additionally, battling in a scenario with a high experience yield, such as a boss fight or an experience-rich raid, can help achieve this goal. Always check game-specific strategies, as mechanics vary widely between titles.