Marvel vs Capcom 1 encounter secret characters help

[krctoday]

I got the Dreamcast version of Marvel vs Capcom 1 and I need help/explain/guide on how to encounter the secret characters.

I got Orange Hulk and Lilith, but every time I tried getting the others characters, I fight Orange Hulk.

Can you please help.

[Dylan]

For Red Venom:
1. Change your leader at the start of every stage by holding one punch button.
2. Get the first Attack in all stages.
3. Get 6 Character Switch Finishes (HP + HK) and a Special Partner Finish (MP + MK), without losing a character in any match before reaching Stage 6.

For Gold War Machine:
1. Get two Character Switch finishes (HP + HK) without losing a character in any match before reaching Stage 6.

For Roll:
1. At every stage, use your Special Partner (MP + MK) at least once.
2. Get 2 Character Switch Finishes (HP + HK) and a Special Partner Finish (MP + MK), without losing a character in any match before reaching Stage 6.

For Shadow Lady:
1. At every stage, use Special Partner (MP + MK) at least once.
2. Get a Character Switch Finish (HP + HK) in every stage and a Special Partner Finish (MP + MK), without losing a character in any match before reaching Stage 6.

EDIT: You can always use codes if you don't feel like jumping through the hoops