It's been hinted at through Masses to Masses 1 and 2, Ian jokes to Kaidan that they're in a relationship, they've been close the whole time, Ian feels jealous when he sees Garrus around Shepard...just saying, there might be something there.
By the end of Mt M 3, even Shepard will get Ian's alias (Deadpool) wrong.
This will result in Ian flying into an unstoppable rage and single-handedly destroying Tarak's gunship. Or just yelling like a madman.
Averted, since Ian's alias changes to Archdemon by the end of Mt M 3, and his dossier calls him that.
There will be a chapter where Ian goes crazy and channels the real Deadpool.
He will be aware of his fictional status, ramble about chimichangas, talk out loud to voices in his head and generally be crazy. The chapter will be called 'Ian vs the Fourth Wall.'
The end of the first chapter leaves this possibility open. Ian's loyalty mission will involve revenge against Garm and will serve as an Establishing Character Moment either by Ian taking revenge in a brutal way (cementing his growing status as an Anti-Hero) or letting the law deal with him (like he did with Saleon).
and Mass Effect: The Guardians