Dragon Shadow

Enchant creature
Enchanted creature gets +1/+0 and has fear. (It can't be blocked except by artifact creatures and/or black creatures.)
When a creature with mana value 6 or greater enters, you may return Dragon Shadow from your graveyard to the battlefield attached to that creature.

Cessation

Enchant creature
Enchanted creature can't attack.
When Cessation is put into a graveyard from the battlefield, return Cessation to its owner's hand.

Despondency

Enchant creature
Enchanted creature gets -2/-0.
When Despondency is put into a graveyard from the battlefield, return Despondency to its owner's hand.

Dragon Scales

Enchant creature
Enchanted creature gets +1/+2 and has vigilance.
When a creature with mana value 6 or greater enters, you may return Dragon Scales from your graveyard to the battlefield attached to that creature.

Screams from Within

Enchant creature
Enchanted creature gets -1/-1.
When enchanted creature dies, return Screams from Within from your graveyard to the battlefield.