The player may join the covenant upon meeting certain requirements, after which they can be summoned by a wider range of players, and gain the 'Praise the Sun' gesture and 'Lightning Spear' miracles.
His 'summon sign' glows gold rather than the typical white, and he rewards the player with 'Sunlight Medals' for a successful co-op fight, due to his membership in the covenant called the Warriors of Sunlight. He also offers to provide assistance for various bosses during the course of the game. His world and the player's come into contact at various times during the game, and he gives the player a White Soapstone item during his first meeting so that the player can be summoned into other worlds as phantoms and 'engage in jolly cooperation'. Like the player character, Solaire is an Undead who journeys to the land of Lordran from his homeland of Astora, albeit on a personal mission to 'find his very own Sun'.