Simon and Nia, battle-weary and worn out, illustrated by Sushio (すしお) as part of a set of MOVIC (ムービック) stick posters. The illustration appears again in the art book Gurren Lagann Art Works (Amazon US | JP).
Tengen Toppa Gurren Lagann (天元突破グレンラガン) illustrations by series character designer Atsushi Nishigori (錦織敦史), in order as featured in each Volume of the DVD Box Set! The last one is so heart-warming, it makes my heart melt.
Tengen Toppa Solvernia and Tengen Toppa Yoko SP, originally illustrated by Yoh Yoshinari (吉成曜) for the back cover of the Rakugaki Core Drill 2.75, make a second appearance in The Art of Yoh Yoshinari Illustrations (Amazon JP).