"Let's Gohdain" could be a reference to "Let's Volt-in" from Voltes V, and it might also be a common signature phrase for a couple other combiner robots /tokusatsu shows.
@Kuraiaku That's a different thing that is written & read differently in Japanese but is written exactly the same when romanized.
Army otaku: 軍オタ (軍: army, read: "goon")
Gundam otaku: ガンオタ/ガノタ (ガン: "Gun", the first two letter of the Japanese word for Gundam (ガンダム), read: "gun")
Interestingly...