Digimon Rumble Arena 2, known as Digimon Battle Chronicle in Japan, is the sequel to Digimon Rumble Arena and has a similar style of gameplay as Super Smash Bros. Melee, except with a health meter. Digimon Rumble Arena 2 is based on the Digivolve techniques of Digimon battling it out in a battle royal and to see who is the strongest Digimon.
The game features characters from the first four seasons of the anime: Digimon Adventure, Digimon Adventure 02, Digimon Tamers, and Digimon Frontier. Each one has their own special moves and "digivolutions", as well as slightly varying normal attacks and taunts.
Agumon: It has a mix of weak and strong attacks, but good variety in his Pepper Breath attack. He digivolves to Greymon and WarGreymon.
Gomamon: Weak offense fast. Gomamon digivolves to Ikkakumon and Zudomon.
Biyomon: Has an advantage with speed, but low on offense and defense. Biyomon digivolves to Birdramon and Garudamon.
Flamemon: He has high defense good offense and good speed. He can digivolve to Agunimon and BurningGreymon.
Gabumon: A slow, but very offensive oriented Digimon. His digivolutions are Garurumon and MetalGarurumon.
Guilmon: Somewhat weak physically, but is very quick on his feet. His special attack, Pyrosphere moves forward and has a bit of a setback. His digivolutions are Growlmon and Gallantmon.
Gatomon: She is the 2nd fastest character in the game and also can paralyze their enemies. Her Digivolution line consists of Nefertimon and Angewomon. She is the only character who starts as a Champion level.
Patamon: Low statistics, but it's the fastest character in the entire game. Patamon digivolves to Angemon and MagnaAngemon
Palmon: She is fast and attacks with poison and the dust of sleep. Togemon and Lillymon are the digivolutions.
Tentomon: Fast and strong in both offense and defense, Tentomon can digivolve to Kabuterimon and Mega Kabuterimon.
Veemon: Limited range on all attacks, but powerful. His Vee-Headbutt, Vee-Knock-Out, and Vee-Punch moves can be very harmful. Flamedramon and Imperialdramon Fighter Mode are the digivolutions.
These are characters that are not available at first, but have to be unlocked by fulfilling certain conditions. All "Black" Digimon have the ability to absorb energy while grabbing the opponent.
BlackAgumon: A virus version of Agumon, with a slower, more powerful normal attack. He can digivolve to BlackGreymon and BlackWarGreymon. BlackAgumon is unlocked by beating the game with two different characters, or beating BlackAgumon during a "Surprise Attack".
BlackGabumon: A fire version of Gabumon. He can digivolve to BlackGarurumon and BlackMetalGarurumon. BlackGabumon is unlocked by beating the game with two different characters, or beating BlackGabumon during a "Surprise Attack".
BlackGuilmon: A black version of Guilmon. He can digivolve to BlackGrowlmon and ChaosGallantmon. BlackGuilmon is unlocked by beating the game with two different characters, or beating BlackGuilmon during a "Surprise Attack".
Duskmon: Well balanced, with one attack with infinite range, and another with teleportation. Duskmon is unlocked after his defeat in 1-player mode.
MaloMyotismon: Has a strong defense and melee attack. MaloMyotismon is unlocked after his defeat. His Ultra move, Pandemonium, scrambles the controls for other characters.
Diaboromon: Has a spin attack, and can fire a projectile as large as itself. His Ultra move, System Failure, de-digivolves other Digimon, and if the Digimon are already in their Rookie stages or cannot digivolve, it will do damage to them if the Digimon are near Diaboromon when he uses System Failure.
Omnimon: Well balanced, and able to perform quick combo attacks.
Neemon: Is fast, but has weak attacks, with often comical effects.
These characters are not playable but play a big part during different modes of the game.
Calumon: Calumon returns from the original Rumble Arena game, now the main character in the game's Crazy Chase mini-game. In the mini-game the players must give chase to Calumon and touch him 20 or above times to win. Calumon also makes cameos during the loading sequence of battles holding info boxes of random character information.
Phantomon: Phantomon is the only minor Digimon to make an appearance. He is a rare powerup known as Summon Phantomon. He randomly appears and stalks a Digimon. If a Digimon touches Phantomon, he'll instantly KO it with his Shadow Scythe. It is seemingly impossible to kill him, but he disappears after a set amount of time has passed.
D-Reaper: Although the character never appears, the stage Chaos Wastelands is fought inside the D-Reaper. The Jeri clone can be seen flying in the background.
Source: Wikipedia, "Digimon Rumble Arena 2", available under the CC-BY-SA License.