Staring at the grimoire, Marcus gained the ability to view and manipulate the memories of others. In order to change a memory, he has to be holding the target. Recent memories are easier to change, only requiring a few seconds of contact, while for much older memories, it can take as long as half an hour to find the memory.
After finding the memory, he has to verbally state what changes he made. He has to be clear with the change is, though for things he doesn't say, the mind itself fills in the blanks. This ability cannot affect some if they have perfect memories, are not organic, or are aware of his ability. in the case of immortals exceeding 100 years, they can be affected, but have knowledge that something in their mind has been changed.
After finding the memory, he has to verbally state what changes he made. He has to be clear with the change is, though for things he doesn't say, the mind itself fills in the blanks. This ability cannot affect some if they have perfect memories, are not organic, or are aware of his ability. in the case of immortals exceeding 100 years, they can be affected, but have knowledge that something in their mind has been changed.