The Selurin is one of the more controversial and poorly balanced cards, because its doubling can lead to Total Attack Values in the hundreds.
Also, he looks like Brad Pitt.
Selurin Magician (Level 1)
The Magician has a Magical Attack +2, and as a trait, all items and Magical Attack spells gain Magical Attack +1.
Selurin Warlock (Level 2)
The Warlock has a Magical Attack +2, and doubles the Magical Attack of all revealed cards (including this Selurin and other revealed Selurins).
Seluring Theurge (Level 3)
The Theurge has a Magical Attack +2, and doubles the Magical Attack of all other revealed cards (including this Selurin and all other revealed Selurins). Additionally, as a Dungeon: ability, the Theurge can cause all players to discard a hero or reveal that they have none. If a hero is discarded, you may borrow it for the turn.