Reminder Urizen and Vergil are the same person and Vergil is still fully responsible for the deaths of a city's entire population after he's healed.

V was just a fraction of himself he cut off. V was a separate new being apart from Vergil. Urizen wasn't "born," Vergil expelling V from his body turned him into Urizen. This also means World of V is canon and he can summon V at will.