Percival

 is one of the Knights of the Round Table.

Profile
Percival was a member of the Knights of the Round Table, led by King Arthur, holding the 2nd Seat.

Camelot: The Sacred Round Table Realm
Percival and the other Knights, apart from Bedivere and Galahad, are summoned by the Lion King. The Lion King tells them to choose to either help her with her "Holy Selection" or side against her, giving them a half a day to think. Percival politely talks with all other knights and then weeps alone afterward.

Percival ultimately sides against the Lion King, being killed in the following battle against his fellow knights.

Abilities
Summoned as a Heroic Spirit, Percival would be the "cream of the crop" when it comes to Heroic Spirits, like the other Knights of the Round Table. He could be summoned through the pieces of the Round Table.