Dr. Arthur Conan Doyle

Combat Alchemy: By expending a use of
Alchemic Concoction, Dr. Doyle can grant
either 1d4 or 2d4 to a roll. Choose the roll to
augment, then roll 2d4. If both the numbers
are either both evens or odd, your
augmented stat gets the rolled bonus. If each are different (one number is even, one
number is odd), take the higher number to
your augmented stat.