Marine Angemon and War Greymon were the MVP’s for like 70% of my first playthrough.
Marine Angemon for the MP management passive, her main move Ocean Love which heals a big chunk of HP for all the battling members plus removing all abnormal statuses all in one and then for the last Great Challenge quest I had her using Safety guard because Omni Sword is a bitch that loves one hit KO-ing for 5 turns your entire team if unprepared.
War Greymon was mostly the one killing everything in one or two hits thanks to Acceleration Boost and Great Tornado’s overpowered damage that also penetrates defenses. Also a reason of why last boss kinda felt easy to me lmao. I got Mastemon literally like at chapter 18 or 19 I think so it was at end game but she also helped a lot, also had a similar job from Marine Angemon in my team, having Final Aura for healing everyone, Safety Guard for those crucial moments but she also had Support End for ruining plans to some bosses support skills and Perfect Revival/Revive for welp, reviving the battling members if they died because of a mistake.
UlForceVeedramon also had him near end game and his purpose was his passive: “Makes sure you always move first in battle” He also had some interesting stuff just in case the boss typing was stronger than my battling team called Character Reversal changing their typing and giving me the advantage right away. Also has Texture Blow to Dot some enemies.
MirageGaogamon made sure I won the Vaccine vs Vaccine battles since he’s a Data type and a very good one, plus he’s one of my fave Digimon too since Digimon World Dawn/Dusk days so yeah, I had to put him in Cyber Sleuth’s team as well lol. Platinum Numemon was there for the X2 exp gaining when I needed to level up someone fast. Putting PNumemon in the front for battles in those cases.