Mega Man Battle Network 6 Cybeast Falzar

Because this is a game where after you beat the boss you can fight it again but now go to undernet 2 and i believe you can open a door and go in graveyard and if you have 200 standerd chips you can fight bass SP.

First of all, its because that is the place where you last saved. Second, since they already showed you an epilogue, there would be no reason to start another part of the storyline. Instead, you have the opportunity to fight the final boss whenever you want, or the choice to complete the after/sidequest and get secret chips and bosses. The idea is to add more to the game experience as a whole; though you beat the final boss, you can still 100% complete it if you want. Besides, you can see the falzar symbol at the start screen so you know that you beat him. I hope that this helps...

... I beet the game to it's just like 1, 2, 3, and 5. 4 you get a new story to complete with v2 viruses and then another story with v3 viruses.

like Theinvisblesun said it is to add more experience to the gaming and
if u didint get all the chips in the game(like ALL of it) it gives u a chance to get
the things u didnt get, so basicly if u didnt get everything, u get everything and
it might show u a secret ending to the game or sumthing like that
or just the satisfation of knowing u beat it =)