I loved vandal hearts, but I don't think I played 2.
Have you tried switching to another mode, like to OpenGL? If you try OpenGL, the two most significant items to try are offscreen drawing and alpha multipass.
If that doesn't work, I recommend you play through it on another emulater like epsxe on PC. You could also try epsxe for Android if you want to buy it. You'll need to have your game saved to memory card, not save state. You can take the memory card from /sdcard/.FPSE and copy it to your PC. Epsxe for PC will be able to use it ... Though you may need to rename the file extension, I'm not sure. When done, resave, then copy the file back to your Android device (rename extension again if needed). I would backup the original memory card file before over writing it. I don't know if epsxe for Android can use the same memory card as FPSE, I don't know what it uses. I assume it uses the same format files as the PC does, so it should work, but I don't know.