Soulbond (You may pair this creature with another unpaired creature when either enters the battlefield. They remain paired for as long as you control both of them.)
As long as Thundering Mightmare is paired with another creature, each of those creatures has “Whenever an opponent casts a spell, put a +1/+1 counter on this creature.”
Near Mint - $1.100
Lightly Played - $900
Moderately Played - $800
Heavily Played - $700
Damaged - $600
Near Mint Spanish - $1.100
Lightly Played Spanish - $900
Moderately Played Spanish - $800
Heavily Played Spanish - $700
Damaged Spanish - $600