Sustain-y sneakiness? Like, at night.

Hi everyone, new player here, forgive my complete and total noobness. :3
So. Uhm. I was trying to come up with something cheap and semi-consistent for gauntlet grinding and this...this deck thing happened. Like, the idea behind this is kinda obvious: try to put a couple unblockable units on the board, boost them up with some weapons (Surgeon's Saw/Lethrai Falchion for sustain purposes) and try to win as fast as possible.
Now, it is kinda working. Kinda. I won about half the gauntlets I tried with this deck and when I draw the right hand things go really smooth. But, overall, this deck is still not as consistent as I would like.
And here I am. Like, I'm open to suggestions if anyone feels like it. 'Cause, you know, it's not like I'm swimming in shiftstone right now. u.u

EDIT:
So, day-after editing, 'cause I realized the deck was kinda all over the place.
I felt like deck was too slow in some cases, and that most losses were due to that. 'Cause I had not enough control and ended up getting steamrolled while waiting for a fatty or a Lethrai Falchion.
I also came to the conclusion that Lethrai Ranger does not have a place in this deck, seeing how my intention is to get past my enemy defenses, yes, but I mostly rely on unblockable units to do that. In the end, since I wanted to speed-up the deck and get some more control without falling back to primal/feln cards (I’m useless with 3 colours decks), I thought nightfall/deadly blockers would be an acceptable alternative.
So I changed the 2 Lethrai Rangers for 2 Nocturnal Creepers. They have both deadly and nightfall which is optimal; I was internally (‘cause I don’t speak to myself aloud thank you very much) debating the merits of Baying Serasaur and Lunar Magus but, in the end, I’m not trying to win the game/sustain with these units, I just need more blockers, and nightfall. There’s really no point considering Duskwalker, deck doesn’t really have that many high cost cards.
I ended up switching the 2 Cull the Deck (which didn’t really work, like, at all) for 2 Twilight Hunt that work well with the deadly units and have the added benefit of nightfall.
Switched 2 Shadow Sigil and 1 Time Sigil for 3 Amethyst Waystone, the end. For the moment at least.
I’m thinking about also taking the 2 Cabal Rogues out of the deck, they are not impactful at all, but I still don’t have any cheap alternative.
Still open to any ideas, let me know what you think of this. :D

EDIT 28/08/2018 :
Removed the Cabal Rogues in favor of 2 Lumen Defenders.
Gave up 1 Ashara, the Deadshot ('cause I was honestly sick of drawing her every two/three turns) in favor of 1 Twilight Hunt.
Adjusted the power base removing a Shadow Sigil and adding an Amber Waystone.
I consider myself done with this deck for the moment. I think I'll come back to it once I have more shiftstone to spend. Or when I learn how to make three coloured decks work.
Enjoy!