With the creation of New Mobotropolis, the dome around Robotropolis was modified, creating a land line to the new city that allowed it to process the radiation for power. The Iron King set out to destroy the protective dome; this threatened both New Mobotropolis and the environment. Thus the soldiers of Fort Acorn, now led by Amadeus Prower, attempted to defend the region; however, despite their fervent efforts, the nearly-invincible Iron King shrugged off their attacks and destroyed the majority of the fort. Commander Prower and the injured soldiers were evacuated to New Mobotropolis. Despite the fort having fallen, Sonic and Monkey Khan were able to trick the Iron King into leaving the dome intact. (StH: #207)