I've never played this game but here is some info I found for you. Hope it helps you.
If you are lucky and your friends list loads, recruit friends, or Bros, in the Bros - Bro Buffs menu. Bro Buffs aid in increasing your stats, coins and XP when you play. The more Bros you have on your friends list, the better. Your friend will be much better than the AI bro and will probably have better fire power and armor.
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