Cheat codes for easy routing: https://wescastro.com/codetwink/cheats.codetwink.com/gba/view/5331/default.htm

From save state 4: https://www.dropbox.com/s/4lfokpb41cdkppz/YUGIOHWWE_AYWE00.ss4?dl=0

1. Odion
2. Tea (mash A)
3. Mai (left 1, mash A)
4. Joey (mash A)
5. Weevil (mash A)
(Ghoul announcement)
6. Kaiba (A, right 2)
7. Mokuba (mash A)
(Duelist Weekly)
8. Duke (A, right 1)
9. Strings (A, right 1)
10. Bakura (A, right 1)
11. Keith (down 1, mash A)
12. Pegasus (down 1, mash A)
13. Yugi (A, right 1)
14. Trusdale (mash A)
(Duelist Weekly)
15. Marik (down 1, mash A)
16. Arkana (A, right 1)
17. Ishizu (up 1, A, left 1)
(passenger: left 1, A, right 1)
18. Shadi (mash A)
19. Umbra & Lumis (up 1, A, right 1)
20. Espa Roba (mash A)
(Duelist Weekly)
21. Rex (up 1, mash A)
22. Rare Hunter (down 1, A, left 1)
(passenger: down 1, A, right 1)
23. Mako (left 1, mash A)

-----

From save state 1: xxxx

NEW ROUTE:
1. Odion
2. Arkana (A)
3. Tea (A)
4. Marik (A)
(2) 5. Shadi (A, right 1)
(DW)
6. Bakura (right 1, A, left 1)
7. Strings (A)
8. Mai (up 1, A) 
9. Umbra & Lumis (right 1, A)
10. Kaiba (down 1, A, right 2)
(Ghouls announcement)
(3) 11. Duke (down 1, A)
12. Trusdale (A, right 1)
(DW)
13. Pegasus (left 1, A)
14. Rare Hunter (A, right 1)
(4) 15. Rex (up 1, A)