make the roof low so all the parts get clumped up for double or triple damage, use nights edge, your friend needs to use obsidian with spinal tap to kill the hungries or bee armor with a bunch of imps, for you use the hellstone armor for fire blocks immunity, get the terraspark boots so you can outrun the wall (for both of you), or you can do what speedrunners make the roof low and dynamite the bridge to do massive damage