Boutmon's profile has been translated and it looks like a perfect Ultimate for *Boy*... if he were to be solely influenced by Verge, but seeing as how the votes let Sparks train him as well and how *Boy* now has his speech patterns I think Sparks influenced him too much for this to be viable.
"A Digimon that has evolved from data from fighting competitions such as karate. He is a polite sportsman who has learned all the rules of martial arts and values fighting in the game format that his opponent wants. There is a wide variety of techniques used by Boutmon, but sometimes not only sports but also non-existent techniques such as fighting games pop out.
Its Special Moves are
Raigekisho, which puts the heel drop into the opponent's brain with lightning, and
Budenhadan, which shoots oversized energy bullets from both palms. Then,
Jinrai Kaitengeki is a series of kicks and punches that does not give the opponent a chance to fight back."
Boutmon is an honorable martial artist willing to fight on his opponent terms and honestly feels like an Ultimate Verge would evolve into if it were a thing back then.
I mean Raigekisho would be Vortex Kick, Budenhadan the Beast King Fist variant, and Jinrai Kaitengeki a Kurenai Shishi no Mai variant that works like Speck's Apnea Rush.
But I digress as *Boy's* potential Ultimate this seems like a possibility considering that he trains under Verge a martial artist maniac and takes pride in the Maul Style, but Sparks' might have influenced him too much for me to think that Boutmon would be his Ultimate form.
Maybe if the Digimon that's going to be spliced into *Boy's* core was a GrappLeomon or some other martial artist Ultimate but its a Gigadramon.
And now that I've gotten into the subject I might as well expand into *Boy's* other potential evolutions the Aegiochusmon variants or as I think of it the Digimon equivalent to Eevees.
First is the standard Aegiochusmon or going by how the others are named the Red variant. This Aegiochusmon is composed of Dramon data and is a possibility because *Boy* has spent a lot of time with Xia a Larvovomon and is going to use a Gigadramon for his splice and also he knows this technique.
"What's it called agan… aha! Charging Strike!" The Aegiomon kicks off with an audible supersonic *boom*, and aerodynamically speeds right into the heavy bag.
Charging Strike is one of Aegiochusmon Red's attack which might be foreshadowing or just the result of Verge putting him through Highland Fang training.
Next is Aegiochusmon Blue and is composed of Cyborg data and the reason this is a possibility is because *Boy* has been hanging around the Machine Precinct when we found him plus Bulwark is home to numerous Cyborg Digimon and also because Gigadramon is a Cyborg.
Lastly is Aegiochusmon Dark which is composed of Evil species data which translates to the various Demon/Devil types, the Waru variants and any/all Digimon who are described as wicked/malicious in their profiles.
This is a possibility because lets face it *Boy* has mostly been around Digimon who would qualify for that with Verge who has been described to have an evil aura and has been filled to the brim with Lust corruption, Sparks his other master is a Demon Man Digimon and is similarly corrupted with Lust as seen with his womanizing ways, and his caretaker Ogremon is theorized to be a downgraded Titamon who is born out of the hatred of the defeated foes of the Olympos XII and wields a SkullGreymon Greatsword which screams evil species and at the very least has Digitamamon as his Ultimate a Nightmare Soldiers field Digimon.
*Boy* is also shown to have been corrupted with the Sin of Lust based on the fact that he's been ogling Ardat here.
"To lay out a caveat my Knight… your student has made a habit of staring at us-at me whenever we're in the same room."
Finally is the fact that Gigadramon also qualifies for the Evil species data like it did for the Dramon and Cyborg data, I mean its literally called dark dragon in its profile and its a purple variant of Megadramon who's power is explicitly called wicked in its profile and both are called the epitome of a computer virus while Aegiochusmon Dark's special ability is that it can generate viruses despite being a Vaccine.
Also one of Gigadramon's attack is Guilty Claw which means it shares an attack name with NeoDevimon.
So basically out of this entire list I think the most likely Ultimate for *Boy* is Aegiochusmon Dark which will fits in nicely with the fact that he hates the Iliad Aegiochusmon who is the Holy variant.