Obviously Teclis is far more potent than a normal mage and the following rules apply to him:

Teclis begins the battle as a Level 4 Wizard and as long as the last potion he drank was Sariour, this will remain the case. However, while he is under the influence of Charoi he will only count as a Level 1 Wizard. If he imbibes his draught of Sariour he will return to being a Level 4 Wizard. Teclis may use either High Magic or any of the lores from the Warhammer rulebook. Whatever lore he chooses, Teclis will know all six spells, regardless of his current level.

Teclis may re-roll all dice for spell effects. For example, if he casts Fury of Khaine he may re-roll the dice to see how many hits are caused and then re-roll any which fail to wound.

Instead of the normal definition of the circumstances that end a remains in play spell, when Teclis casts such a spell it will remain in play until it is dispelled, or until he chooses to end it (which he can do at any time), attempts to cast the same spell again or is slain. This means that Teclis can maintain more than one 'remains in play' spell at a time.