Having recently come back to EDH after a few years Yahenni instantly stood out to me, both lore wise and for the sheer efficiency of the card.
You mention Kormus Bell, and I apologize if it has been brought up before but have you considered Massacre Wurm to compliment your Bell and general theme of removing opponents creatures?
Another favorite addition of mine is the particularly obscure Tombstone Stairwell, which all by itself turbo accelerates your Yahenni engine or other cards that care about creatures dying.
Personally I find Bucher of Truth to be the superior option as far as Kozilek is concerned. The Great Distortion's on cast ability has a higher ceiling but asks more of you deckbuilding wise and Butcher is much more powerful if you get to untap with him.
Because your mana base is a actual consideration when adding any color. Is stirrings fundementally improving your aggro MU? Sure you get Decay but I'm not convinced dipping into green is better than having access to Path and Souls when talking about splashes. Not to mention superior options in the board.
Personally I prefer the consistency offered by staying monocolored as my meta is very hostile to stumbling on ones own manabase. Adding any color adds versitility but it's especially not as easy a consideration to make, especially when we haven't pinned down the best version of what is essentially a archetype in it's infancy.
EDIT: Dredge is hardly a MU that I would use to formulate an opinion on since that is the epitome of lobsided if I've ever seen any. I will say that Ashiok strikes me as unimpressive.
In the history of Control as an archetype, rarely if ever has the term "being proactive" translated into adding a slew of average 2 drops to your control deck. Dragonlord Ojutai is being proactive, adding Hand of Silumgar and Stratus Dancer is being a worse something else.
We already have a deck with powerful two drops, Thoughtseize and removal, it's called Abzan Aggro, and the deck has been doing really well for weeks.
I don't think it's possible in such a warped environment. There is very little you can do to a resolves Hydra other than leaning on Vault and attempting to get to your non blue Dragons. Hydra is a rough card to face, the reason I dismiss it is because it's a pretty awful card against the field.
Honestly if multiple people jump on the Hydra plan in my LGS, I'd just play something else entirely.
Went 6-0 in games across two events this weekend. Surprisingly didn't drop a game against Mono Red or the other aggressive decks I came up against and not surprisingly trounced Sultai Whip, Abzan Midrange and Esper Control, Raptor/Den Protector be damned.
The mighty morphing duo seem a lot less impressive when you're dropping actual bomb s and they're trying to outdurdle/race you.
You mention Kormus Bell, and I apologize if it has been brought up before but have you considered Massacre Wurm to compliment your Bell and general theme of removing opponents creatures?
Another favorite addition of mine is the particularly obscure Tombstone Stairwell, which all by itself turbo accelerates your Yahenni engine or other cards that care about creatures dying.
Personally I prefer the consistency offered by staying monocolored as my meta is very hostile to stumbling on ones own manabase. Adding any color adds versitility but it's especially not as easy a consideration to make, especially when we haven't pinned down the best version of what is essentially a archetype in it's infancy.
EDIT: Dredge is hardly a MU that I would use to formulate an opinion on since that is the epitome of lobsided if I've ever seen any. I will say that Ashiok strikes me as unimpressive.
We already have a deck with powerful two drops, Thoughtseize and removal, it's called Abzan Aggro, and the deck has been doing really well for weeks.
Honestly if multiple people jump on the Hydra plan in my LGS, I'd just play something else entirely.
I'll start worrying about that when people actually start using the card, and as that seems unlikely, I'm not going to start worrying.
fixed that for you
Now is it dominating? Maybe, maybe not, but people downplaying it's lingering significance are delusional.
The deck is still very much relevant.
The mighty morphing duo seem a lot less impressive when you're dropping actual bomb s and they're trying to outdurdle/race you.
Dissolve is a nod to the mirror if nothing else.