Hints:

Fight vs. AJIM / Play as AJIM:
     To  battle  AJIM,  you  must  have a time limit set (not on Death
Match).  Win the first one or two fights by gaining a health advantage
and  then  letting  the  time  expire.  When  an upward-pointing arrow
appears  over  your  next  opponent  as  the  round  begins, AJIM will
descend, destroying your erstwhile challenger and attacking. This will
happen  usually  by  the  third battle. AJIM is very tough to beat, so
pick  your best character and hang in there. To control AJIM, you must
challenge  and defeat him as described (can't win by time-over). After
beating   AJIM,  finish  the  game  by  completing  all  missions  and
destroying TANGRAM. Now, you have to set the clock in BOTH your DC and
your  VMU  to February 15-30, 2000. Any month after Feb. is also fine,
but  AJIM is only available when your clock reads the last half of any
month  later than January, 2000. To select AJIM in any mode, go to the
Random  Select  icon and hold both Turbos. AJIM will appear and can be
chosen

Alpha Temjin:
     Beat  the  game  using  Temjin  in  Fog  Mode  without  using any
continues on any difficulty setting. Then after saving the game, enter
Dreamcast  5.45 Mode. Now at the Character Selection screen, highlight
Temjin  and  press  Left  Turbo.  Then  highlight the Random Character
option  and  press  Left  Turbo.  Then highlight Raiden and press Left
Turbo  twice.  Then  highlight  Bal  Bados  and press Left Turbo twice
again.  Then  highlight  Angelan  and  press  Left  Turbo  twice. Then
highlight  Grys-Vok  and press Left Turbo 3 times. You'll hear a sound
if done correctly. Now choose Temjin.

New Game Mode:
     Beat  the  game  with  all  default  characters on any difficulty
setting  and  any  number  of  continues  left  and  view  all  ending
sequences.  Now when the game is played again, an Arcade MSBS 5.2 Game
Mode will be unlocked.

Bonus End Sequence:
     Enable  the New Game Mode (see above), then beat the game without
using any continues with any character and play mode.

Alpha Raiden:
     Successfully  complete  the  game  as  Raiden in fog mode without
using  any  continues  under any difficulty setting. After the game is
saved,  enter  Dreamcast 5.45 mode. Highlight Apharmd-B and press Left
Turbo  at  the character selection screen. Highlight Dordray and press
Left  Turbo  twice.  Highlight  Specineff  and press Left Turbo twice.
Highlight  Fei-Yen Kn and press Left Turbo twice. Highlight Cypher and
press  Left  Turbo  3  times. A sound will confirm correct code entry.
Select  Raiden  to play as a white and yellow version with no turbo or
air dash attacks.