Prowess

Whenever you cast a noncreature spell, conjure a card named Monastery Mentor onto the battlefield.

Thunderbond Vanguard's power and toughness are each equal to the number of creatures you control.

Each creature token you control enters as a copy of this creature.

Attacking tokens you control get +1/+0.

Whenever you cast your first creature spell each turn, that spell gains mobilize 2.

As an additional cost to cast this spell, you may behold a Dragon.

Target player discards a card with the greatest mana value among cards in their hand. If a Dragon was beheld, exile that player's graveyard.