Hello everyone

I would like to clarify how the response ability of the stark character Follower of the many faced god works.

Can i stand a stark character after i play the Follower or the Follower has to be already in play and trigger the response by playing another stalwart character?

Thank you in advance

Short answer: Yes you can.

Longer explanation: Cards can trigger themselves as long as they qualify for the play restrictions of their own ability.

This card CAN trigger itself when it comes in because the Response window would open AFTER the card was played. So, you have played a character with the Stalwart keyword from you hand (itself) so you can trigger its response to stand a Stark character.