Ultraman: V2 from the Start

[Semi-invincible protagonist + one heroine] Shaoyang, an Ultraman fan, dreamed of a little girl in red shoes who told him to save the world. After taking the blue sapphire cone she gave him, Shaoyang immediately… (It was a dream, after all, and he was an Ultraman fan. You know how it goes.) He raised his transformation device and shouted, “Gaia!!!” When Shaoyang woke up, he found that he had transformed into Gaia V2, with a Tiga lying beside him… Shaoyang: “I’m fighting a Tiga? I’m not cheating… Oh, I’m Gaia V2 now, which means…” Tiga: “Huh? I’m fighting Gaia SV?” Shaoyang thought he’d be able to steamroll the opposition in the Tiga world, but discovered that things there weren’t so simple. The space-time demon Etelgar, the giant demon beast Maga-Orochi, even the primordial Space Beasts and the Absolutians had all come to this planet. Tiga (furiously pounding the table): “I’m so screwed!” Gaia (looking invincible): “SSV, activate!” [Worlds visited: Tiga, Mega Monster Battle: Ultra Galaxy Legends, Ultraman Ginga S, Ultraman Dyna: The Return of Hanejiro, Mega Monster Battle: Ultra Galaxy, Ultra Zero Fight, Ultraman Cosmos, Ultraman Max, Mebius, the Legendary movie, the New Generation…]