thats a good question...hmm i think after you beat these two domains which are pretty basic,you get parts from the boss digimon.talk to a tamer named mark schults,give you a toyplane(at the tamers club) gives you some advice about the domain called bios domain.in that domain he tell you of a metalgreymon(an ultimate)use the toyplane mark schults gives you(hint: in some boxes you will find toycars,use them with toyplane to catch metalgreymon. you will it incounter on one of the floors.it run away ofcourse, but you see it on the last floor.hint:dont beat the boss digimon(always save your game before a big battle) before you catch metalgreymon or you will lose it forever.