Kadena, Slinking Sorcerer
{1}{B}{G}{U}
Legendary Creature -- Snake Wizard
3/3
The first face-down creature spell you cast each turn costs {3} less to cast.
Whenever a face-down creature you control enters, draw a card.
Trail of Mystery
{1}{G}
Enchantment
Whenever a face-down creature you control enters, you may search your library for a basic land card, reveal it, put it into your hand, then shuffle.
Whenever a permanent you control is turned face up, if it's a creature, it gets +2/+2 until end of turn.