Bartholomew is an unseen antagonist of Rewrite.
His appearance is not mentioned.
No one talked about Bartholomew openly but given that he was willing to sacrifice thousands of orphaned children in an experiment it can be said that he is either an exteme realist or a power hungry sadist.
Several years prior to the current events of Rewrite, Bartholomew was a figurehead of Guardian and he secretly had his team of scientists and researchers conduct experiments on orphaned children at a place called Santa Brosia. The main goal of the experiment was to produce a subject capable of surviving in the world 1000 years from now; which is full of poison from the Earth running out of energy and to also produce an Anti-Key weapon. The fruit of the experiment was Lucia who could not only survive in such a world but her body could also produce a poison that was strong enough to kill almost any living creature. Eventually he was found out by the main branches of Guardian; the main branch in Vatican called for the experiment's immediate termination and most of the people involved were disposed of, though Bartholomew somehow escaped the assassination along with his associate, Brenda.
- In Rewrite Harvest Festa it is believed that Bartholomew had a hand in creating Lucia's clone, Akari Konohana.