Gurren Lagann - Episode 20 of Back Arrow has a What else?

Episode 20 of Back Arrow has a "What else? COMBINE!" Reference from Gurren Lagann. Kazuki Nakashima was the writer for both Gurren Lagann (2007) and Back

Episode 20, Tengen Toppa Gurren Lagann Wiki

If I explain what happens in Back Arrow, will someone watch it? Please? – Day with the Cart Driver

Tengen Toppa Gurren-Lagann - lurkmore wiki

Kamina, Tengen Toppa Gurren Lagann Wiki

Am I the only one that noticed Rei and Asuka in episode six??? : r/ gurrenlagann

Gurren Lagann ep. 20, How Far Will God Test Us? Review - Fresh Takes #19, RPC

Tengen Toppa Gurren Lagann (Gurren Lagann) · AniList

Gurren Lagann – 15 – Random Curiosity

School's Out!! Gurren Lagann Episode 20 & 21 Reaction & Review!

A Rewatch to Pierce the Heavens - Tengen Toppa Gurren Lagann Episode 20 Discussion [Spoilers] : r/anime

Went to watch peak (part 2) in 4DX today : r/gurrenlagann