Although Matt and Keith have not had much screen time together, they are seen working together in A New Defender. The two characters lead separate teams on an large-scale mission, where the Paladins are in immense danger; they're desperately attempting to fly Voltron away from Naxzela, a planet that Haggar has made to become a bomb. Keith realizes that Naxzela is a trap for Voltron, and using a Galra fighter, he takes off to attack the Galra fleet, gathering the rebel ships still available along the way. Keith and Matt are in communication with each other, when Keith heavily implies—then attempts—that he's going to sacrifice himself to stop Haggar by flying his own ship into the barrier surrounding the ship Haggar's aboard, and therefore stopping the bomb. Matt screams for Keith not to. Fortunately, Keith is saved by Lotor, shooting the ship instead.
Katt is a rare-pair in the Voltron fandom, though it became slightly more popular after season 4.
Some fans often theorize that Keith and Matt knew each other while at the Galaxy Garrison, mostly due to their mutual relationship with Shiro. Following the events of season four's A New Defender, of Keith's heroic-suicide attempt, fans also like to theorize how Keith and Matt would interact after.
|SHIPS||het||Allurance • Allurivan • Hallura • Hidge • Hunay • Hunelle • Jamonica • Kacxa • Kallura • Kidge • Komelle • Krolidad • Krolivan • Leiffin • Lotacxa • Lotura • Mallura • Nymatt • Plance • Romatt • Romance • Shallura • Shidge • Zaggar|
|slash||Adashi • Corance • Hance • Heith • Jaith • Katt • Keitor • Klance • Koliveith • Lancelot • Latte • Shance • Sharkon • Shatt • Sheith • Shendak • Shlav • Shoran • Shotor • Shunk • Svance • Svav • Sveith • Uliro|
|femslash||Acxlura • Kromelle • Pallura • Romura • Shayllura • Veracxa • Zezor|
|poly||Jeiro • Klunk • Pallurance • Sheitor • Shkatt • Shklance|
|CHARACTERS||m/f||Allura • Hunk • Keith • Lance • Lotor • Matt • Pidge • Shiro|