The Third Part (Unus Annus/Jacksepticeye)

Mark should of known. He should of known Unus and Annus would appear as egos. Yet, he didn't even think.

With his new ego and one of Ethan's first, he introduced them to his own iplier egos and let Unus stay with them in the manor.

Unus and Annus keep to themselves a lot. Dark growing suspicious of them and over hearing them talking about their 'Third part' He gains curious and goes to ask Mark about it.

Mark has no idea and even asks Ethan, who also is confused.

Unus and Annus soon disappear and go to find their missing part.

That same day...

Sean goes missing