Inserting the custom portrait was easier than i thought.
I´m a bit lazy, so i just slighly edited the default character to look a bit closer to me. Is not a great work, the shading is still kinda off, but i´ll do.
The only problem i had is that i can´t change the tactician colour pallete in battle animations, any idea how can i do that? Can i use Nightmare with FE7 modules? If the answer is yes, then what character is the tactician replacing so i can edit it?