Truthseeker

Void (Whenever this card is target of a spell or ability, you may change target to another non-Land permanent you control instead)

When Truthseeker enters, choose a color.

Whenever an opponent draws one or more cards, he/she reveals those, they lose 2 life and you gain 2 life for each card revealed this way not of the chosen color.

Whenever an opponent discards a card not of the chosen color, they lose 2 life and you gain 2 life.