Evolve: Draw 1 more card for each Void you draw. Stacking Evolves can allow you to draw 2 more cards when you draw a Void.
Exhaust synergies can use Void as exhaust fuel. In addition, any effects you may gain from exhausting a card are fulfilled at the end of the turn, since Void is Ethereal.
Medical Kit allows Void to be played and exhausted for no penalty, though they already exhaust at the end of your turn, and their effect is applied on draw. One of the only scenarios in which such an interaction would be relevant is with Dark Embrace.