Brothers in Arms

"An analysis of this Darkmess Puddle, reveals that it will take the skills of a long range specialist to overcome. FIRST to volunteer! Luigi Luigi_icon_MRSOH.png representin'! That's my BOY! There! You see? Mario Mario_icon_MRSOH.png - the original! ALWAYS has his brother's back! Woop! Woop!"

- Beep-0

Brothers in Arms is a side-quest that appears in Mario + Rabbids Sparks of Hope, located on the planet Pristine Peaks. It is found after taking a secret path to exit one of the caves, by using Beep-0's Wave Power to destroy a cracked wall, revealing the path. It is a Darkmess Puddle battle, and Luigi and Mario must be used for the battle, but the Sparks that the heroes can bring can be chosen. After the battle, the quest is complete, and the player is awarded a Planet Coin, the Steampunk Sharpshooter, and the Memory for Luigi.

The quest's name is a term that refers to soldiers that fight together in a war, albeit used in a more literal sense as Mario and Luigi are actually brothers.

Battle
The battle is always random, but the battlefield is always large, having a long path that the bros. must traverse. The enemies that appear are Scopers, Lone Wolves, and Flamin' Stooges. More can appear from Darkmess Portals. After the area is reached, the battle is won.