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And his previous form, War Growlmon, is clearly based on an Evangelion Unit from Neon Genesis Evangelion. His final form is an even more blatant reference to Evangelion Unit 01's winged form from End of Evangelion.
In the American dub, Henry Wong's sister's name is Suzie. As in The World of Suzie Wong.
Episode 26 in the American dub is titled "Kazu and Kenta's Excellent Adventure", most likely a nod to Bill & Ted's Excellent Adventure in which two wild and crazy guys also explore foreign lands. Party on, dudes!