Clockwork Bounty-Hunter

{t}: Clockwork Bounty-Hunter becomes untargetable.
{t}: Salvage target artifact or artifact creature. (Exile target spell. Add it's mana cost to your mana pool until your next upkeep.)
When Clockwork Bounty-Hunter is summoned or deals damage, draw a card. If the card is an instant or sorcery, reveal it and it now costs {2} less.