Jim is not like a normal Etemon at all. Where most Etemon have huge egos and also bad singing talents, Jim has virtually no egotistical nature and can sing wonderfully..... That is... If he even knew HOW to sing. Whenever inspiration hits him, he manages to pull off something wonderful for a song only to get rudely interrupted a few seconds later. After working so hard on getting the tone and mood down with a song he's trying to sing, only to have it interrupted by someone else, will usually bring about his very wrath and easily end up saving the day because of it depending on the situation. Or, he could simply make the day worse depending on who interrupted him. During his free time he tries thinking of songs and tries to get the tone correct with a different song each time. Etemon is fairly clever at solving problems, but is usually more notable for his sheer strength as an Ultimate, thus living up to his species's title of King of Digimon. His power increases even further with his digivolution to MetalEtemon, and his singing abilities improve dramatically upon digivolution as well. His ability to slightly mess up reality as Etemon, such as his strength and superspeed whenever he gets angry is a homage to The Mask.
Jim always thinks his digivolution chain is messed up, and Pichimon, among his next two forms, are the reason why he thinks so. He's rarely seen in this form, but usually he's Pichimon whenever he degenerates from MetalEtemon.
Another reason why Jim thinks his evolution line is messed up. He doesn't get confused about why his evolution line is messed up until he digivolves back into Etemon. Jim is degenerated to this form during an encounter with Eaglemon in Episode 1.
While Jim has no reason to complain about his Rookie stage being Goburimon, he still wonders why he digivolves from Bukamon to reach this form. He always thought Bukamon digivolved to Gomamon rather than Digimon such as Goburimon. He first digivolves into this form when helping his other five companion Digimon deal with a Monochromon. When Jim wonders about his Fresh to Rookie forms, he believes it is because he hasn't degenerated to this forms in such a long time that he completely forgot about them.
Unlike most Sukamon, he does NOT have a Chuumon following him around. Also unlike Sukamon, he is rather powerful, and due to this hidden power, he digivolves back into Etemon at some point after Puffy manages to digivolve back into MetalGreymon, making him the second to reach his original Ultimate level form.
At first, Jim has trouble digivolving into MetalEtemon, because in this universe, digivolving into Mega Level for the first time requires accomplishing a great feat or conquering or acquiring a certain emotion. Jim manages to do so when he finally perfectly sings a musical number, which is hilariously joined in on by the other five Digimon as each of them play different instruments while Jim is the lead singer. After digivolving into MetalEtemon for the first time, he learns his singing increases the power of both him and his allies while causing the enemies pain, so often times as a finishing move, he will play a heavy metal song with his friends to completely finish off the enemy. Humorously, he loses this singing ability when he degenerates back to his previous forms, and must digivolve again to MetalEtemon to sing perfectly again.