Mega Man Battle Network 4 Blue Moon - Gameboy Advance
Secret Boss:
------------
To get past the gate in Ura Internet area 5, you need
all 150 regular chips. Once you get past it, you can
fight the secret boss, Forte, and get his chip, Forte Another
Secret Boss SP:
---------------
After defeating Forte in Ura Internet 5, Forte SP can
be randomly encountered in Black Earth 2. He can drop
Delta Ray Edge in Blue Moon, and Black Barrier in Red Sun.
Secret Dungeon:
---------------
There is a large hole surrounded by purple slime on a
platform in Ura Internet area 6. In order to approach
it, you need the chips Bug Curse, Muramasa Blade,
Black Wing, Element Dark and Poison Anubis.
Once you get close enough, it will suck you down to
the secret dungeon, Black Earth.