Samurai Shodown 4 - Cheesing Amakusa Shiro Tokisada

Move back slightly until the screen zooms out. Do a crouching kick by pressing down + D button. Amakusa will respond with a far heavy slash, crouching slash, or his projectile. Jump over Amakusa’s attacks with a jumping deep heavy slash by pressing up-right + C button. Repeat until Amakusa starts teleporting around, then just evade him and his attacks until time runs out.

Samsho 4 - CPU Exploit: The Crouching Kicks Never End

For anyone wanting specific ways to defeat CPU characters in this game, please also see Samsho 4 CPU Strategies - Google Translated from Japanese

Several characters in Samsho 4, most notably https://dreamcancel.com/wiki/Samurai_Shodown_IV/Haohmaru and https://dreamcancel.com/wiki/Samurai_Shodown_IV/Genjuro, have infinites. If your chosen character has an infinite, learn it and abuse it.

Samurai Shodown 4 - Dream Cancel Wiki

Samurai Shodown 4 - Cheesing Minazuki Zankuro

Just press forward + AB buttons simultaneously to walk forward and then circle step when Zankuro gets close and is about to attack you, then do a standing heavy slash. Ideally do it while Zankuro is jumping too since he throws out empty jumps a lot if you aren’t attacking. Repeat until you win.

Nakoruru: Example of Circlestepping and Heavy Slashing CPU Zankuro Again and Again until You Win

Also, when you run / dash towards any of the CPU characters, CPU Zankuro included, they will always try to slash you. While you are running / dashing, you can react to this slash by deflecting it (216D or 2146D motion) or by using Jubei’s catch counter.

Samurai Shodown 4 - Cheesing Your Rival Character

The previously described Circlestepping and Heavy Slashing Strategy also works against your rival character whom you fight after CPU Amakusa and CPU Zankuro:

Nakoruru vs CPU Genjuro, Her Rival Character