Goblet of the Oath is the sixth stage of The Legend Ends.
The battle starts off with two Pigeon de Sables and an UltraBaaBaa, shortly followed by a Two Can. Then two more Pigeon de Sables and three more UltraBaaBaas spawn. About 20 seconds after that, a Youcan appears, and the UltraBaaBaas go on a cycle of two every 20 seconds. Very soon the Pigeon de Sables spawn every 10 seconds. Eventually, the Two Can and Youcan respawn.
This stage is hard, almost impossible without Wave Blockers. Use Octopus for the Pigeons, then summon either Cat Machine Mk 3 or Eva Unit-00 if you have them with meatshields, a Barrier Breaker and a good attacker for an easy win. If you don't have a Wave Blocker, the use of strong Barrier Breakers with area attack like the Elemental Pixies will be a necessity.