Okay, so first and foremost, if you're looking for a controlling build, you really need to generate card advantage. Typically this is done with blue or black providing some means of added card draw, but in Mardu colors, your only quality options are in black (my how we miss
Underworld Connections). But, before we go jamming 4x
Read the Bones and 4x
Sign in Blood and all that into the deck, another way to generate card advantage is to make 2-for-1 or better plays, where your removal will actually take out more than just one target. In this capacity, you actually have access to all of the best options available in standard, namely
Drown in Sorrow,
Anger of the Gods,
End Hostilities, and to lesser degrees
Extinguish All Hope and
Fated Retribution.
That much being said, I think the build is currently sub-optimal. It's on the right path, but it really lacks these means of generating card advantage. Sadly
Chandra, Pyromaster is a bad option here, as her +0 ability will end up hitting your removal spells a lot of the time and you might not have legal targets or might not want to use that particular piece of removal at that specific time... as a result, you end up exiling your removal options and limiting your lines of play for later in the game.
So, how can we shape this thing up? I would propose the following changes:
1) Completely move
Bile Blight to the SB. Most commonly this is just a 1-for-1 card and, honestly, you have plenty of those available. You can side it in if someone is running a deck with tons of redundancy where you feel it is beneficial.
2) -1x
Hero's Downfall and +1x
Mardu Charm. Downfall is good, but Charm gives you the ability to go on offense with the tokens or even to make the opponent discard during their draw phase.
3) -1x
Utter End. This is really just too mana intensive to really be efficient. It's nice to have 2x in case you need one in a pinch, but I wouldn't go more than that.
4) Obviously if you have them you can swap
Despise with
Thoughtseize as it's just a better card, but, in the event you don't have the cards or $60 to just drop on cardboard,
Despise will work in a pinch.
5) -1x
End Hostilities. It's the premier sweeper out there at the moment, but I'd much rather free up that spot for
Anger of the Gods.
6) Move
Suspension Field over to the SB and fill those slots with
Banishing Light. Sure, it costs 1 more, but it can hit anything outside of a land and that versatility is what you're looking for.
7) -2x
Chandra, Pyromaster see above, and -1x of both Sarkhan and Elspeth (I'll explain this one in a minute).
8) -2x
Lightning Strike. It's nice and cheap, but Anger will hit more than one creature and odds are that you won't need the burn given your win conditions.
So you're currently sitting with 11 open slots to add cards.
9) +4x
Anger of the Gods. It's so much cheaper than
End Hostilities and will just HOSE any aggro build and, outside of Courser, neuters Mono-Green Devotion.
10) +3x
Stormbreath Dragon. Sure, it's like more Sarkhans, but the pro-white is relevant a LOT and it's just another threat the opponent will have to deal with.
11) +3x
Read the Bones. While I personally like
Sign in Blood in more situations, the BB mana requirement is a bit harder to hit reliably, so bones it is! This will give you the full suite of them so that you can really dig for cards.
12) +1x
Liliana Vess. She'll help punish opponents who have stuff in their hands, can help tutor up that board wipe you need, and, in the event you can ever get her to ultimate (while the opponent is worrying about Elspeth or Sarkhan), she'll just win the game given the fact you've been filling the opponent's yard this whole time. Even in a worst-case scenario, she makes the opponent focus on her life total and not yours for a while.
Anyway, those are the changes I'd make. I can't say I've played a ton with the KTK cards, but given the limited exposure I've had, this will work much more effectively than what your previous list had.
I hope it helps. Good luck!