Complex sentence: His'true' form has blue skin, black horns and hair, red eyes, with a marbled appearance and two scars that only appear in this form, one being a hand print on his neck, the other a line from throat to navel.
Split into simpler sentences: His'true' form is to have blue skin, black horns and hair, red eyes, with a marbled appearance. He also has two scars that only appear in this form, one being a hand print on his neck, the other a line from throat to navel.