The glum bloke in Firelink Shrine has a more interesting history than you might expect.
Dark Souls 3: Hawkwood and dragon transformation
Hawkwood is resident at Firelink Shrine when you first arrive, and can be found either seated on the stairs or outside the side entrance near some graves. His dialogue reveals a little about the Undead Legion and Farron Knights. He can be summoned to aid you in the Oceiros boss fight.
Speak to Hawkwood when you first arrive at Firelink Shrine to receive the Collapse emote.
Speak to Hawkwood after defeating the Abyss Watchers to receive the Farron Ring.
Sometime after defeating the Abyss Watchers, Hawkwood will leave Firelink Shrine. Hawkwood's Shield can then be found near the graves outside the shrine.
To progress Hawkwood's quest, touch his summon sign near the third bonfire at Archdragon Peak. If you collect the Twinkling Dragon Torso Stone from Archdragon's Peak and then speak to Andre the Blacksmith, you'll be able to duel Hawkwood at the Abyss Watchers bonfire. If you win, he'll give you the Twinkling Dragon Head Stone. If you lose, he'll take the Twinkling Dragon Torso Stone from you. You can come back and have another go to try and win both stones, though.
It is permitted to refer to Hawkwood as "Awkward" on any and all occasions. He is available for summoning in the Consumed King's Garden.