Cloudshift is Momentary Blink for 1, but has no Flashback.  I swapped out the Kor Skyfishers for another Blink and 2 of your old friends the Scepters.

Ideally, you'd want a Venser the Sojourner in here somewhere too, but you told me not to splash blue, so I didn't add him.  As it is, your Vivid lands will get him out, but if you do include him it'd be worth revamping the deck and making it Esper.

Unquestioned Authority and Confessor are the only two cards that keep this from being a Modern deck.  Confessor can be replaced with Liliana's Caress or Spirit Cairn; Authority can be replaced with Brave the Elements, Bathe in Light, or frankly just removed.

Edit: What was I thinking?  I replaced Unquestioned Authority with Blind Obedience.  That gives you extort on top of control. 

I also replaced Confessor with Vizkopa Guildmage.  Turning your lifegain into opponent's life loss is more in line with the Orzhov than turning discard into lifegain.  That said, if you really enjoy the Felidar Sovereign win, you can either get Confessors to have the extra one-drops for the Charm, or more Suture Priests, which are frankly better.

Now the only thing keeping this from being Modern is Carnival of Souls, in the sideboard.

I'm not sure about the mana base for this deck.  It has the bare minimum 30%, and some Carnival of Souls in the sideboard just in case, but will it be enough?  Get back to me on this.

If you find yourself with too much discard power, swap Ravenous Rats/Liliana's Specter for Wall of Omens.  That way, you can still gain card advantage, but more reliably.

Swap Mantle of Leadership for Cathars' Crusade if you want to play for a longer game.  Mantle is better with Liliana, but Crusade's bonus adds up over time with Knell, if it is not removed.

Use Flickerwisp instead of Azorius Arrester for synergy with Suture Priest's passive.  Arrester provides stronger control than Flickerwisp, though.