X-Agumon has fast attack speed and average attack. Very usefull for hunting wild digimon. X-agumon is vaccine type. So you must prefer to kill virus digimon type. You will receive less damage from virus type digimon.
Agumon-X -> Geogreymon -> Rise Greymon -> Shine Greymon -> Burst Mode
Lalamon attack is weakest, but has a lot digi soul. So you can do more Skill on Lalamon. Lalamon is Data type digimon, find vaccine didigmon to face on battle.
Lalamon -> Sunflowmon -> Lilamon -> Rosemon -> Burst Mode
Rookie digimon is level 1-10. After getting to level 11 you can digivolve your Partner digimon to champion. Then you can digivolve to Ultimate on level 21. Mega digimon will open on level 41. And last is burst mode type will open on level 65, but partner digimon must level 71 to unlock this mode. You will need Accelerator Item to make burst mode.