Wo Long: Fallen Dynasty

You will find a large amount of 4* pieces in the final few missions of the game, so this shouldn't be too difficult to accomplish. You'll also get a full set of 4* armor and a weapon by unlocking the Merit beyond Measure (15G) achievement, leaving only one other weapon and an accessory to find. You can use your accolade points to purchase loot boxes from one of the NPCs at Mt. Tianzhushan for a chance at a 4* item as well. Once you have a 4* item in all seven slots, the achievement will unlock.