Nemesis of Reason is a red flag for me, and feels like it could be Jace, Memory Adept for your environment. You have a slower environment with a less than robust removal package. You will probably find it being drafted outside of any archetype concerns as a bomb.
I really like Codex Shredder as fair two-way mill support.
What do you want out of the archetype? Is it partially about making Ipnu Rivulet more dynamic?
I'm also curious to hear about the Morph package. Can you tell me a little bit about its inclusion? It stands out to me some as maybe a bit insular and could possibly be cut to open up for more flexible options. I haven't fully familiarized myself with this new list, it is just something that I noticed when scanning.
On the topic of mini-archetypes, I feel like I support a pretty wide range of archetypes in my cube. It's something I really prioritize in my cube design. I use the term fringe archetypes rather than mini, because it is more conducive to how I approach things.
In my experience, maximizing fringe archetypes mostly comes down to:
- Curating a suite of mechanics/themes that:
---- have maximum overlap with one another
---- that have relevance to most if not all colors
---- can be represented in a variety of theaters of play (aggro, midrange, control, combo)
- Committing to those mechanics in cube real estate
- Identifying cards that exploit the intersections of those mechanics in unique/axis-shifting ways (these open up the fringe archetypes)
- Editing out unnecessarily insular mechanics/themes
Editing down may sound a bit contrary to the goal of creating more mini archetypes, but I suppose that I'm challenging the implied compartmentalization that the term "mini" implies. That three cards constitutes an archetype.
I find that when themes are prevalent enough to become part of the foundation on which your archetypes are structured, it becomes easier to leverage the intersecting points into completely different styles of decks. This increases repeated play value and creativity.
So take for instance, I have heavy land, discard, and draw themes in my cube...I commit maximum space to making these themes a foundation for which the entire cube meta operates which can make a card like:
completely shift the way a deck operates. Suddenly a control deck starts turbo-cycling for an Approach of the Second Sun kill....or the Wildfire deck I'm drafting morphs into some bizarre ramp deck via Splendid Reclamation. It becomes a deck-defining card, but only because there's a dense supporting structure for it. I'm sure I could've used a less wacky example, but this was the first one that popped into my head. Hopefully it makes sense.