Sheoldred, Torment Epitomized

At the beginning of each opponent's upkeep, they
choose one:
• Put a -1/-1 counter on each creature they
control and they get a poison counter
•That player reveals their hand. You may choose
a card from among it. That player discards that
card and gets a poison counter.
At the beginning of your upkeep, gain control of target creature or artifact. If it's a creature, it
gains infect.