[Graphics] CAMBIARE.... IL PROTAGONISTA???

Hello everyone: I wanted to ask you a hand because I just wanted to make a "change of character" on my Pokemon Red Fire Rom (in Italian), or reverse the protagonist and the rival, using the latter as my character controlled, so I imported the sprites from the other rom, Pokemon Gary Oak's Mod, in that of Red Fire, in order to reverse the characters, only that just turned on the rom, my character has some strange colored lines when he is still, and when he walks he is always the same; can you help me? I do not want to change anything else in the rom, just the characters, and I also wanted to see you how to change the body of the character, when I start a fight, or I would like to see the body of the rival and not that of the protagonist Thanks in advance

it's hard to understand what exactly is going on, can you attach screenshots? player is poorly displayed in the intro, when you give the name of an opponent?