There have been a lot of comments on this deck already, and I admit honestly that I did not read the majority of them. However, this was the most recent deck listed on the Advertise Your EDH Deck thread, so I'll add my two cents anyway, for what it's worth.

Really, though, the only thing I can think of that's not already on your list is that you have plenty enough creature kill capability to successfully run cards like Waning Wurm, Rotting Regisaur, Clackbridge Troll or Yargle, Glutton of Urborg.

Also, I might mention that I've always liked Sudden Death, Deathstroke and the classic Terror and Rend Flesh as removal.

That's all I got. Cheers!

In any mono-black deck I always suggest Withering Boon. It's so unexpected and you can cast a kill spell to counter another creature from the yard.

The recent change for Oubliette makes it amazing in EDH. Since it phases out, if you target their commander they can't chose to put it back in the command zone. Locking them out of their commander until its removed or you lose.

As far as finding expensive cards to cut, I guess I'd have to suggest Liliana of the Veil first and foremost. It's incredibly expensive and its not super strong in commander. I get that you don't mind discarding instants and that her minus ability allows you to cast them, but if you're looking to be more budget-friendly I'd suggest cutting that one first.

After multiple testing I will have to agree about liliana. While powerful in modern, but in edh no so much. Your opinion on Koskun Falls?

Dang, this is a really cool take on Toshiro. If I didn't like Creatures so much, i'd definitely give this kind of build a spin!

One question, I noticed on an old update you mentioned that Desecration Demon worked relatively well in the deck. I run a very Creature heavy version of Toshiro "Instant Tribal" - Toshiro Umezawa - EDH PRIMER that you commented on with some good suggestions, and i'm always looking for good cheap threats.

I've read that Desecration Demon is usually really bad in EDH (and other formats) as people can just sac creatures to keep him tapped until they find an answer for it. My thought was that it might be a positive for a Toshiro deck, as them sacrificing to him would give me Toshiro trigger, if they don't they get hit with a 6/6 Flier, and if they do use removal on it, it's only a 4cmc creature anyway...

It's a really cheap card that I might get one to try out anyway, but i'd rather learn from someone else's mistakes is possible ;)

When I was using a lot of creatures in my old variant, you'll be surprised what they sac for Desecration Demon plus the fact if they see a dangerous instant in the grave and have no answers, they would rather take 6 damage to the face. It's fun adding painful choice cards like Choice of Damnations or Virtus the Veiled just so a instant can trigger. Sometimes it's more fun experimenting underrated cards for nasty effects