Jack Bros.

Jack Bros. is a duo competitor in the King for Another Day Tournament. The duo consists of Jack Frost and Mothman from the Megami Tensei series and its numerous spin-off games such as the Persona series. They were added in as a unique fan submission.

King for Another Day Tournament

 * "He may be small, he may melt under even the slightest bit of heat, and he may ho, but Jack Frost sure isn’t going to melt under this pressure. Armed with some weak Bufu skills, his pal Mothman’s piercing gaze, and just a couple of Life Stones to their names, they’re ready to give this contest a shot. Today the Shinjuku underground, tomorrow the world!"
 * —Jack Bros.' description on the MOJO!!

The Jack Bros. were revealed at the end of "Narrow Road (Beta Mix) - Falsion". Their source list includes rips related to games developed and published by Atlus such as Shin Megami Tensei and their spin-off games like Persona and Devil Summoner, Etrian Odyssey, Catherine, BlaZeon and more.

The Jack Bros faced Mariya Takeuchi and King Dedede and won both times. In Round 3, they were defeated by The Jazz Cats, then eliminated by Rhythm Masters.

Quotes
Lines without a link come from the "All Vs/Victory Lines" video.

Trivia

 * The name "Jack Bros." is a reference to a Virtual Boy Megami Tensei spinoff game of the same name.
 * The reason for Mothman's inclusion in this team has to do with Pyromide, a SiIvaGunner fan and moderator on the Discord server, since he uses Mothman as his profile picture, and he was heavily requested to be in the tournament.
 * Jack Bros. were the first characters to be interviewed by Meowth and Unregistered HyperCam 2.
 * They were the only team who managed to beat a Final Four contestant (that being Mariya Takeuchi) without making it into the Final Four themselves.

Quotes

 * A lot of their quotes give reference to the Megami Tensei series as well as its spin-offs, including its characters, music and other references.
 * Their vs. quote against Metal Ajit Pai references Jack Frost's dialogue from the game .
 * Their victory quote against Metal Ajit Pai references the Persona 4: The Golden Animation song "Ying Yang".
 * Their victory quote against Geno references Alice, a demon present in the Megami Tensei series.
 * Their vs. quotes against Off the Hook ft. Paruko and Nintendo Power references the game , a Megami Tensei spinoff game for the Virtual Boy.
 * Their vs. quote against "Weird Al" Yankovic references the character Mr. Thriller from Shin Megami Tensei II, who is modeled after Micheal Jackson's appearance in the "Thriller" music video.
 * Their victory quote against "Weird Al" Yankovic as well as their vs. quote against MissingNo. references Mothman's dialogue from the game .
 * Their vs. quote against Pitbull and the Aliens references the  song "GROOVY".
 * Their victory quote against Pitbull and the Aliens as well as their vs. quotes against Papyrus and Law & Disorder all references Jack Frost's dialogue from the game Shin Megami Tensei: Digital Devil Saga 2.
 * Their vs. quote against Law & Disorder also references the character Teddie from .
 * Their victory quote against Men in Black references the Sea of Souls, a recurring location in the Persona series.
 * Their vs. quotes against Thanos and Dr. Robotnik references the Life Stone, which is a Recovery item in the Megami Tensei series.
 * Their vs. quote against Wario Partners, LLP references Jack Frost's dialogue from the game .
 * Their victory quote against Wario Partners, LLP references Mammon, a demon present in the Megami Tensei series.
 * Their vs. quote against King Dedede and The Jazz Cats references the Phantom Thieves of Hearts.
 * Their vs. quote against The Jazz Cats also references a line said in Catherine and from one of Yu Narukami's quote in Persona 4.
 * Their victory quote against King Dedede references the song "Beneath the Mask" from .
 * Their vs. quote against Soild Snake references the Snake race in which they are demon-like serpents and dragons.
 * Their vs. quote against Quote references the Kirijo Group who are a globally operating multinational trading company that appears in the Persona series.
 * Their vs. quote against Adam Levine references "The Fool" arcana in the Persona series. It also refers to a recurrent phrase used on social medias. A reference to the Maroon 5 song "Makes Me Wonder" is also made here.
 * Their vs. quote against Johnny Bravo references Jack Frost's dialogue from the game .
 * Their victory quote against Johnny Bravo references the main location of Persona 4, Inaba.
 * Their victory quote against Mr. Krabs references the "Burn My Bread" meme, originating from the  song "Burn My Dread".
 * Their vs. quote against Mariya Takeuchi references the character Lady in Black from Shin Megami Tensei III: Nocturne due to their monochrome like appearances and the Persona 5 Royal song "Colors Flying High".
 * Their victory quote against Mariya Takeuchi references the Persona 4 song "Heartbeat, Heartbreak".
 * Their victory quote against Dr. Robotnik references the Shin Megami Tensei III: Nocturne song "Fierce Battle".
 * Their vs. quote against Daft Punk ft. Pharrell references the Demonica, which is a device and a set of equipment featured in the Megami Tensei series.
 * Their vs. quote against Jack & Elmo references Akihiko Sanada 's All-Out Attack quote in Persona 3.
 * Their vs. quote against HOBaRT references the Underworld, a location in Shin Megami Tensei II.
 * Their vs. quote against Rhythm Masters references the game .
 * Their victory quote against Rhythm Masters references the Dark Hour, a major plot and a gameplay element in Persona 3 and its remakes.
 * Their vs. quote against Nico Nico references The Midnight Channel, a major plot and a gameplay element in Persona 4 and its remakes. A reference to the Gachimuchi film Junkyard Boyz is also made here.
 * Their victory quote against Nico Nico references Mara, a demon present in the Megami Tensei series.
 * Their vs. quote against Donkey Kong references Hanuman, a demon present in the Megami Tensei series.
 * Their victory quote against Donkey Kong references Thoth, a baboon-like demon present in the Megami Tensei series, while also referencing the "Begone Thot" meme.
 * Their victory quote against The Jazz Cats references Nekomata, a demon in the Megami Tensei series.
 * Their vs. quote against Eminem references his alter egos Marshall Mathers and Slim Shady as well as the mention of the wild card from the Persona series.
 * Their victory quote against Off the Hook ft. Paruko references the "Bros Before Hoes" trope.
 * Their victory quote against Nintendo Power references the song "Hoes Mad" by Famous Dex, which has become a meme within the  community.
 * Their victory quote against ZUN references the character Cirno, an ice fairy from the Touhou Project series.
 * Their victory quote against Thanos references the movie The Santa Clause 3: The Escape Clause, in which the main antagonist is based on the folklore character Jack Frost.
 * Their victory quote against DJ Professor K references the ancient record the Devil's Contract from the game Jet Set Radio.
 * Their victory quote against Adam Levine references the Maroon 5 song "Happy Christmas (War Is Over)".
 * Their victory quote against Daft Punk ft. Pharrell references the song "Human After All".
 * Their victory quote against Papyrus references the Skull Crusher weapon from the game Etrian Odyssey IV: Legends of the Titan.
 * Their victory quote against Jack & Elmo references an incident where a moderator on the SiIvaGunner Fan Discord server, Pyromide, accidentally stepped on a child in an airport.
 * Their victory quote against Dr. Piccolo references the Trauma Center series, specifically the ability Healing Touch and the GUILT virus from said series.
 * Their victory quote against Eminem references the end of D12's "My Band", especially the appearance of the salsa at the end.