I think I have an idea... --- Creatures have myriad for your opponents. (Creatures not attacking you have myriad. They can't create tokens attacking you or one of your teammates this way.) ---
5Color--I would recommend a tool boxy commander or one that is like Tazri and only multicolored in text box. 4Color--Recommend Not Blue since Saskia was underwhelming compared to the others 3Color--One of the Khans block tribes since the others were done in Commander product more recently than the Alara ones 2Color--All the guilds have big fanfare, Selesnya, Dimir, Gruul, Azorious, Rakdos were not in Commander 2015. Most flexible spot so would base choice here on what isn't covered by the others. 1Color--Black is the best monocolored, so either Black or try making viable Red/White.
So, simplified, what I'd prefer for doing one deck for each number of possible colors:
5Color All but Blue Temur Azorious MonoBlack
If you did 3, 2, and 1 like @modnation675 recommended (I feel like it was tossed out since you had a specific card in mind):
Abzan Temur Azorious Rakdos Monoblack
Black would have an extra rep, but most of the color combinations could use a bit more variety in commander options. So each main commander would offer what that color doesn't really do right now with Legendary creatures but could do.
Other ideas
Card type matters (Artifact, Instant, Sorceries, Enchantment, Creatures, Lands) Plane based (Innistraad, Zendikar, Tarkir, Alara, New Phyrexia, Theros, Ixalan, Amonkhet) Imagine how epic 5 new planes(or even 1) from Commander products would be just saying Specialty Mechanic themes (Flip Cards, Planeswalkers, Split cards, Vehicles) Interaction with a theme or concept in different ways (time, thoughts, elements)
These factions cover all colors equally and playing types. There is a competitive faction (WUBR), a janky faction (WUBRG), an aggressive faction (RG), a mid-range faction (B), and a late-game faction (WUG). In addition, these tribes cover new design space while staying true to the color pie.
Axlatl, Reality Cipher WUBRG Legendary Creature - Elemental When ~ enters the battlefield, choose a number between 1 and 6.
Whenever a player casts a spell with converted mana cost equal to the chosen number, draw a card, then that player draws a card and chooses another number between 1 and 6.
Hey, sorry I haven’t been on in the last 20 or so hours, I was traveling. I had a few ideas of my own... I don’t think we should do mono blue for the one color because it doesn’t support itself too well at anything but control. Neither does white or red do the same easily. Green and black are the only other options then. I think we should do a mono black thing because Ob Nixilis was the least played commander from C14 and mono black needs another go. That means we have to go blackless for the four color deck... any ideas? For five color I was thinking spirits to be honest. It is an underplayed tribe despite the fact it has a whole block (Kamagawa) dedicated to it. I don’t know about 3 or 2 color.
@Gelectrode Only thing you'd need to make sure of is the following. --- Whenever a player casts a spell with converted mana cost equal to the last chosen number, [Effect]. ---
Comments
Are eminence abilities okay, if they aren't busted.
---
Creatures have myriad for your opponents. (Creatures not attacking you have myriad. They can't create tokens attacking you or one of your teammates this way.)
---
Otherwise, they don't get the benefits.
4Color--Recommend Not Blue since Saskia was underwhelming compared to the others
3Color--One of the Khans block tribes since the others were done in Commander product more recently than the Alara ones
2Color--All the guilds have big fanfare, Selesnya, Dimir, Gruul, Azorious, Rakdos were not in Commander 2015. Most flexible spot so would base choice here on what isn't covered by the others.
1Color--Black is the best monocolored, so either Black or try making viable Red/White.
So, simplified, what I'd prefer for doing one deck for each number of possible colors:
5Color
All but Blue
Temur
Azorious
MonoBlack
If you did 3, 2, and 1 like @modnation675 recommended (I feel like it was tossed out since you had a specific card in mind):
Abzan
Temur
Azorious
Rakdos
Monoblack
Black would have an extra rep, but most of the color combinations could use a bit more variety in commander options. So each main commander would offer what that color doesn't really do right now with Legendary creatures but could do.
Other ideas
Card type matters (Artifact, Instant, Sorceries, Enchantment, Creatures, Lands)
Plane based (Innistraad, Zendikar, Tarkir, Alara, New Phyrexia, Theros, Ixalan, Amonkhet)
Imagine how epic 5 new planes(or even 1) from Commander products would be just saying
Specialty Mechanic themes (Flip Cards, Planeswalkers, Split cards, Vehicles)
Interaction with a theme or concept in different ways (time, thoughts, elements)
5-Colored deck: Contraptions
4-Colored deck (WUBR): Instant/Sorceries
3-Colored deck (WUG): Group-Hug with benefits
2-Colored deck (RG): Shaman Tribal
1-Colored deck (B): Life-Paying
These factions cover all colors equally and playing types. There is a competitive faction (WUBR), a janky faction (WUBRG), an aggressive faction (RG), a mid-range faction (B), and a late-game faction (WUG). In addition, these tribes cover new design space while staying true to the color pie.
Thoughts?
I like your ideas, but contraptions might be a little odd in 5 colors.
What about CMC-matters?
EDIT: I really like @brcien's idea of plane-theme decks! The only problem with it is getting good art for all the cards.
Sounds interesting, I really want to make some contraptions as well. It's just too bad we can't have the border.
WUBRG
Legendary Creature - Elemental
When ~ enters the battlefield, choose a number between 1 and 6.
Whenever a player casts a spell with converted mana cost equal to the chosen number, draw a card, then that player draws a card and chooses another number between 1 and 6.
"Your days are numbered."
4/6
I don’t think we should do mono blue for the one color because it doesn’t support itself too well at anything but control. Neither does white or red do the same easily. Green and black are the only other options then. I think we should do a mono black thing because Ob Nixilis was the least played commander from C14 and mono black needs another go.
That means we have to go blackless for the four color deck... any ideas?
For five color I was thinking spirits to be honest. It is an underplayed tribe despite the fact it has a whole block (Kamagawa) dedicated to it.
I don’t know about 3 or 2 color.
I don’t know how we would do contraptions. Unstable is only in the format for a few more weeks.
Only thing you'd need to make sure of is the following.
---
Whenever a player casts a spell with converted mana cost equal to the last chosen number, [Effect].
---