Once Human, Now a Parasite

Arthur, a Rich businessman was kidnapped and tortured for months by men his wife hired, after months of this hell, he was given a second chance, a new life in a different world, of course, Arthur would rather start a new life than stay and continue to be tortured, so he accepted the deal that was proposed by THE mysterious individual, but when he finally was reincarnated, Arthur discovered he was a..... parasite?