I would say that if the guy you want back is a serial cheater and addict, then perhaps a deeper question to ask yourself is why you want someone like that back...I think one of the best things about trying to manifest an SP or an ex back is that eventually, we all go from the obsessive glee of finding a technique that will win the person to learning how to truly love ourselves and feel secure within ourselves alone. A lot of times, when that happens, we realize the person we just had to have may not be worth it. These are questions that only you can answer but if your self-love is intact, then you make better, healthier choices in friends and romantic partners.