Tillaric Stormwing
Tillaric was from the world of Oerth.
He had arrived in Sigil two weeks before the Ka-Tet met him, however he claimed he was actually in Sigil 10 yrs before.
At that time he 'misstepped' and ended up in “hell” for 5 years. It was after this he became a Barmy.
He tells that he returned to Sigil 3 weeks ago when he then died.
He recalls being redeemed by St Cuthbert (a god who slays fiends) who gave him a 2nd chance, after which he returned to join The Mercykillers to smite fiends.