Proletariat Guild Mage

Flash, reach.
Imprint: When Proletariat Guild Mage enters the battlefield, you may exile target sorcery card with converted mana cost 3 or less from your hand.
{4}{t}, Exert Proletariat Guild Mage: copy and
cast the imprinted spell without paying its
mana cost. This ability costs {1} less for each
gate you control. If no mana was paid to
activate this ability, copy and cast the
imprinted spell a second time.