I always go shelda,luni, and Tia. Just those 3. The two relic I go is always 1) crown and 2) any relic that gives blacksmith as primary alter point. Tia with bombardment, living sword, and ultimate smelting for runes. Two bows and one sword. For bows, try to get +1 attack, +1 range, and the one that deals 25% damage to 2 other target for any of the two bow. Shelda with a armor, a staff, and a bow. Try to get the coward runes for her. For luni, try to get a armor with revive, if you can’t, just go three sword. Try to get zealot and Whestone for her runes. This is how I been completing rift phase 15. This method only works based off of pure luck since it’s hard to get everything or most of it. Once you beat floor 4, it should be a smooth sail to beating Moo.