I've beaten the game top to bottom, but I can't seem to still find data bug roxas. I know the final boss roxas, but on youtube theres a secret boss called Data Bug Roxas, in one of the system sectors at hallow bastion. Can anyone tell me how to get to him?

Level up scan 3 times, go to Hollow Bastion, enter the system sector, and at the end it Bug Roxas.

Okay, after you've beaten Hollow Bastion , go back to that place again and ten you should be able to detect a new new system sector somewhere. If you want to know where it is, it's where you find that last piece of that segment. But be warmed, there are 13 data trails and some of them are really hard. On the 13th floor, Data Roxas will appear.

It's in a new system sector after you beat the game. It has 13 floors and the 13th is where you battle Bug Roxas. If you get enough points, you may purchase ultima weapon in the end.

There is a Data Bug Roxas!? Awesome, I didn't even know! [Goes to play Re:Coded some more.]

So THAT'S where you get the Ultima Weapon! I'm going to fight him right now.

He has 4 modes, blue yellow red and green

 

Blue normal as in C. O.

yellow x2 speed

red x2 damage

green giant and more hp

 

he has quite a lot of health bars and i suggest using mutiple Judgment triads

WARNING: the hollow bastion system sector is recomended for level 80(megalixer required for first floor i knwo that much)