Reflector

Reflector is a Spark that appears in Mario + Rabbids Sparks of Hope. It is recruited to the player's party upon arriving at Beacon Beach, the first planet in the game.

Reflector's ability is Reflect, which redirects a portion of the damage taken by the player back to the enemy that damaged them. Reflector can be upgraded by feeding it Star Bits, which increases the damage redirected to the enemy. Its passive ability is Attack Master, which increases the damage output of an Hero's weapon-based attacks. The passive ability can also be upgraded.

Reflector is a large blue Spark that uses a floating, brown mirror-like object with a pair of Rabbid ears on it.

Mario + Rabbids Sparks of Hope website
''When Reflector powers up, the enemies better beware! With its help, the attack aimed at the hero is directed right back at the opponent. Ouch.''