Bastion Inventor is a common Creature — Vedalken Artificer card from Aether Revolt (AER), collector number 30. Current market price: $0.03 (foil $0.25), TCGplayer market prices via Scryfall.
Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for {1}.) Hexproof (This creature can't be the target of spells or abilities your opponents control.)