Sinew Dancer

Flying

Corrupted — Whenever this creature attacks, if an opponent has three or more poison counters, creatures you control get +1/+1 until end of turn.

Flash

Enchant creature

Enchanted creature gets +1/+1.

Corrupted — As long as an opponent has three or more poison counters, enchanted creature gets an additional +1/+0 and has first strike.

Vigilance

Corrupted Metalcraft — As long as you control three or more artifacts and an opponent has three or more poison counters, Incisor Steed gets +3/+0.

As long as this creature has three or more counters on it, it has flying and vigilance.

Tap three untapped artifacts and/or creatures you control: Put a +1/+1 counter on this creature. Scry 1. Activate only as a sorcery.

Toxic 1

Corrupted — When Norn's Fetchling enters, conjure a card named Plains into your hand. If an opponent has three or more poison counters, you may seek a nonland card instead.

, : Tap another target creature. This ability costs less to activate if you control a creature with a +1/+1 counter on it.