Here is my take on exile Loest deck:

Hero: Loest, Savior of Layar

Allies (18):
4x Darklight Apprentice
4x Spirit Warden
4x Evolving Abomination
4x Fortified Wisp
2x Thunderstrike Construct

Abilities (10):
2x Sinkhole
4x Fireball
4x Lightning Strike

Items (8):
4x Splicer's Crown
4x Amulet of Conjuring

Locations (4):
4x Racksul: Warped Desert

= 41 cards ~ 19200g

Deck is combining two themes at its core: exiling and homunculus buffing. Once Warped Desert is on the board Splicer's Crown gets insane value. It gives up to 3 draws and +3/+3 cumulative stats for only 2 resources. Homunculus ally line up consists of Evolving Abomination, Fortified Wisp and Thunderstrike Construct.

I chose Abomination over Entagled Wisp for several reasons:
1. Even though it has homunculus package, at only 10 allies it is not enough to make full potential of the wisp.
2. There is no Vigilant Wisp to seek Entangled Wisp. Without that T2 into T3 Entangled is just 3/4 most of the time.
3. With that in mind Abomination is also a 3/4 on T3 but with potential to grow further. This self growth can only snowball further with health buff from Splicers Crown. If it does snowball Abomination can also serve as a fatty in this deck.

Fortified Wisp is a great ally on its own. The damage reduction effect can win games on its own if opponent doesn't have immediate answer. It can easily grow when it finishes allies after you use burn spells on them or with Splicer's Crown.

Thunderstrike Construct is great follow up on T5 into T4 Wisp. And it is another solid ally for Splicer's Crown synergy.

Darklight Apprentice and Spirit Warden are second part of Desert support. Apprentice will generate Shadow Energy from Desert usage and mitigate downside of Amulet. Spirit Warden is a 2/5 that becomes free draw engine with Desert in play if you do not have homunculus/Splicers crown set up. I also feel bit dirty when I play it into Snare Trap (you can actually get snare trap if use desert ability before playing Warden)

While all these tempo efficient draws from Desert are awesome, aside Loest ability, they are limited to opponents allies only. Amulet is there to actually draw some of your own cards to get your comboes going and get spells to control the board (or at end game burn their hero). As I said Apprentice can mitigate sustain cost, but sometimes it is best to use it when Loest is at 0se, so you get 3 cards and Amulet gets destroyed. This way you got 3 cards for 4cc and you do not need to worry about sustain and resources anymore.

Some missing cards:
Supernova. This deck goes more on the midrange/control side of spectre. So most of the time you will use burn for board control and your allies aren't cut for rushing. Because of this I found Supernova not good enough to put in the deck. In situation where I was forced to use it against aggressive decks opponent would just refill the board, and nova deals damage to heroes as well so it puts you dangerously low on health. Instead better gameplan is to control the board early until you stick wisp on board and then start generating card advantage from Desert.

Item destruction. I usually save Loest ability for nasty items but I wouldn't mind having some LLN in the deck just in case. I opted not to put to keep the cards count low. For me, even without that tech deck was good enough to get to and keep me at 300 range.