In Raid Mode, you start with a limited selection of characters, but more can be unlocked by progressing through the main story or by meeting specific criteria within Raid Mode itself. Each character has unique stats and a special ability, making them suitable for different playstyles. For example, Jill might have higher handgun proficiency, while Chris excels with rifles.
As you complete Raid Mode missions, your character earns experience points, increasing their level. Leveling up grants stat bonuses and allows you to equip more powerful custom parts. You also earn Battle Points (BP), which can be used to purchase new weapons, custom parts, and items from the shop. The key to progression is to consistently play missions, upgrade your gear, and experiment with different character and weapon combinations to find what works best for you. Don't be afraid to replay earlier stages on higher difficulties to maximize your BP and XP gains.