Legendary Ruin of Amagoth
"You think your Ruin of Amagoth is enough to trap me?" Slayer calmed down quickly as he stared at the dissipating figure of Regriel that had used the entirety of his being to unleash this power. "I'll break out of this soon enough. Just you see. Your daughter's power will become mine."
"Unfortunately, that won't be happening." Regriel grinned all of a sudden, "This Ruin of Amagoth will exist in an entirely different dimension. It would constantly sap away your strength to birth Magic Beasts."
"You're free to do as you please, but no matter what you do, you'll eventually lose all your power." Regriel roared in laughter as his figure vanished, "This is the ultimate Ruin of Amagoth that I prepared exclusively for you."
"Even if you were to steal my daughter's power, you'll end up losing it too."