Exosphere

Exosphere is a Spark that appears in Mario + Rabbids Sparks of Hope. It joins the Heroes alongside Edge, and is automatically equipped with her during the Darkmess Tentacle battle named Driven to the Edge.

Exosphere's ability is Fortify, which allows all Heroes within range of the user to take less damage from physical attacks and Super Effects. Exosphere can be upgraded by feeding it Star Bits, which further lowers the damage received from enemies. Its passive ability is Athlete, which increases the damage done by move abilities. The passive ability can also be upgraded.

Exosphere is a large black Spark that is always accompanied by three floating shields, which have an orange border and a light-reflecting surface. When Exosphere moves, the shields can be seen rotating around its body, implying that it uses them as its own protection.

Mario + Rabbids Sparks of Hope website
''Next to him, you see Exosphere. When its friends are threatened, it gets defensive. Partner it with a hero to make them more resistant to physical damage and super effects.''