Doc Aurlock, Grizzled Genius

If you’re casting a plotted card from exile without paying its mana cost, you can’t choose to cast it for any other alternative costs. You can, however, pay additional costs, such as kicker costs. If the plotted card has any mandatory additional costs, those must still be paid to cast the spell.

Doc Aurlock’s abilities don’t change the mana cost or mana value of any spell. They change only the total cost you pay to cast spells or plot cards from the appropriate zones.

Doc Aurlock’s abilities can’t reduce the amount of colored mana you pay for a spell or ability. It reduces only the generic mana component of that spell or ability’s cost.