Steward of the Realms Beyond: Whenever a creature attempts to use a teleportation effect or summon a creature within 30 feet of you, you may attempt to block the effect. Make an opposed caster level check (1d20 + caster level) as an immediate action. If the check succeeds, the spell or effect fails and is wasted; otherwise, it is unaffected. You can use this ability once per day plus one additional time for every 5 wizard levels you possess beyond 10th. You must be at least a 9th-level wizard to select this discovery.