Each chest from rusted keys have a chance of 1-2 scraps each. The armor is very nice, tho, especially the godbreaker one. you can get 4 rusted keys, theyre in chests, any youtube video will show you clearly where they are. Eight different Relic Hunter Treasure Seekers minibosses can be found and killed to acquire a Heart of a Hero and sometimes an additional Legendary Weapon Repair Kit or Legendary Armor Patch Kit. The grips are the best heavy STR piece in the game arena champion and last boss, yes.