I honestly can see a Spirits and Chalice of Life deck forming. "Oh look, I gained life and drew a card! Now you lose five life every turn." Ramp with Pristine Talisman for more card draw when you play the Reaver...
Here is an esper list I came up with, black is just to pay Lingering Souls flashback cost. Delver of Secrets is not a spirit, but he is still as good here as he is in illusions.
Signature - Miraculous Recovery
Avatar - Heroes of the Planes
Signature thanks to Hakai Studios
I honestly can see a Spirits and Chalice of Life deck forming. "Oh look, I gained life and drew a card! Now you lose five life every turn." Ramp with Pristine Talisman for more card draw when you play the Reaver...
"Reveal a Dragon"
"Oh you want a free dude? Sure, and give him +1+1 and hexproof as well! SWEET!"
Dungeon Geists might become a finisher as well. It's like love... only far more heartbreaking.
4 Delver of Secrets
3 Snapcaster Mage
4 Drogskol Captain
2 Geist of Saint Traft
Spells: 22
4 Ponder
3 Gitaxian Probe
3 Vapor Snag
4 Mana Leak
4 Midnight Haunting
4 Lingering Souls
3 Oblivion Ring
Lands: 22
4 Seachrome Coast
3 Glacial Fortress
3 Darkslick Shores
1 Isolated Chapel
3 Moorland Haunt
4 Island
4 Plains
Thoughts?