Theorealized Medius (Starlight Rare) [BETB-EN017] Starlight Rare

(This card is always treated as a "Power Patron" card.)
If a "Power Patron" card is on the field: You can Special Summon this card from your hand, then you can add 1 "Theorealize" Spell/Trap from your Deck to your hand. If a monster is banished face-up (except during the Damage Step): You can activate 1 of these effects;
• Add 1 "Ars Magna" card from your Deck to your hand.
• Banish this card, and if you do, Special Summon 1 "Diactorus" monster from your Extra Deck.
You can only use each effect of "Theorealized Medius" once per turn.