I have a few more card suggestions for you to try out.
Spinecleaver is good as some sort of alternative wincons. It may not be good versus burn-heavy decks like the rampant Aggromar, but against swarm decks with weak minions (like Lilithe before she drops Variax) or slower decks, Spinecleaver could be very troublesome to them.
Repulsor works wonders. It’s a semi-removal, and sometimes you can line up good blasts with Repulsor.
You need some form of “pings”. Most people run Blistering Scorn, I use Bloodtear instead (and I think Scorn is actually better, but I don’t feel like crafting it yet). In addition, Bone Swarm is a nice tech to surprise your opponent. It’s quite good against Lilithe, Reva, Zirix, and with Ankh equipped, Argeon. Seeing that you run Rosh-Rak, Bone Swarm deals 4 to your opponent, so you can create some surprise lethal out of that.
You may want some more solid wincons, like Nimbus and Aymara. Nimbus may be a bit too slow considering the amount of burn decks and hard removals in the meta, but by having a crazy amount of answer-or-die stuff, you can exhaust your opponent’s dispels and removals.
Personally, I prefer Spellbender over Emerald Shroud for dispel. Shroud’s body is too weak and only dispel 1 target, while Spellbender packs a stronger body and an AoE dispel - which would come in very hand against a lot of matchups like Obelisk Vet and Cassy.
Instead of Incinera, I recommend you trying out Silhoute Tracer also. Albeit a weaker body and having only a one-time mobility effect (as opposed to Incinera having an ongoing effect), I found Tracer often more helpful than Incinera because: 1. you can pull yourself out of enemy provokes; 2. you can move, attack, then move again with Tracer but not Incinera; and 3. Tracer is 1 mana cheaper - and it helps a lot, because you’re more likely to make game-defining clutch trades in mid game, and the 1 mana difference may be the difference of whether you could BBS in the same turn you drop your Incinera/Tracer.
Card draw wise, I’d suggest you trying out L’Kian, Sojourner and Spellbender also. All of my suggested card draws are bundled with a body, and hence make the card draw effect having a net cost lower than 3 (e.g. L’Kian is draw 2 cards + a 2~3 mana body, so the drawing effect costs less than 3). As a control Sajj, you need more ways to bolster your board presence as you don’t have much board presence to start with - and those card-drawing minions I suggest helps you to acheive that. On the other hand, Divine Spark may be too costly and slow. 3 mana is a huge tax on your early turns’ mana. Facing so many quick decks, I often found myself having no space to play a Divine Spark.
If you have more free spaces to add stuff to your deck, I’d suggest smth like Primus Shield, Starfire Scarab, Dancing Blades and Primus Fist (I opted away 1 Mystic and 1 Pax for 2 Primus Fists).
In the past 2.5 months of my active times in Duelyst, I’ve nearly solely played my makeshift of Control-ish Sajj. I find my own deck surprisingly successful up to Mid-Diamond. I’ve been playing much less about 2 weeks after RotB expansion rolled out, and I haven’t been to S-Rank yet, so my experience may not be that helpful to you especially if you’re in S-Rank or the very competitive and grindy high-Diamond - but here are my two cents anyways.