Final Tower is the third stage in the 47th Sub-Chapter, Ends of the Earth.
At start, Director Kurosawah spawns, along with 3 Metal Doges. After a few seconds Metal One Horn starts spawning infinitely (~20 seconds between each), and at last Sir Metal Seal spawns. 2 Metal Seals are seen in this stage, the two of them spawn one with each Metal one horn. Take care of Kurosawah, he can insta-kill lots of cats with uber-high health.
A metal perma-freeze + shockwave strategie could work, using Hoop cat or Poseidon plus Manic Macho Legs. After a lot of time Kurosawah should die and you just have to use critters to delete the metals left.
Another strat is just crit. all the possible metal enemies in the phase and use Bomber cat to stunlock kurosawah, still spamming critters to conserve the SL after his knockbacks.