Krovikan Plague's oracle wording reads "Tap enchanted creature: Krovikan Plague deals 1 damage to target creature or player. Put a -0/-1 counter on enchanted creature. Activate this ability only if enchanted creature is untapped." under what other circumstances would you be able to pay that cost? is it possible to tap a tapped creature? I was under the impression that the fact that you couldn't was why twiddle and pals needed to gain a "you may".