Xha'Xu, the Delegator --
Legendary Creature - Human Soldier (MR)

First strike, lifelink
, , Return Xha'Xu the Delegator to its owner's hand: Your commander is no longer your commander. Target creature you control becomes your commander.
2 / 2

==xx==

Crown Swarm --
Legendary Creature - Fungus (MR)

When Crown Swarm enters the battlefield, put two 1/1 green and blue Fungus tokens of it onto the battlefield.
Fungus creatures you control have power and toughness each equal to the amount of Fungus creatures you control.
At the beginning of your upkeep, put a 1/1 green and blue Fungus token onto the battlefield.

* / *

==xx==

I think Crown Swarm is a bit too powerful, but this is the third iteration (and it's weaker than the previous two). What do you guys think?

Why is the first guy a ninja?

Crown Swarm- He is too good. When you cast him, immediately you have 3 3/3 on the battlefield, that is if you don't have any others on the battlefield, The second effect is just too strong when you have the two other abilities on it. I would reccomend it being at leas a so that it will still be able to keep its mythic title.

Because he started out as ninja.
He should be a soldier. Good catch.

I can drop the third ability.
He first started out as a Prossh variant; that scaled WAY too well.
Then I toyed with it making copies of itself, but the copies aren't commanders so that didn't work quite like I planned, though I could go back to that. How about...

Crown Spore --
Legendary Creature - Fungus (MR)

The legend rule doesn't apply to this, and
each Spore-Heir you control is also your
commander.
Spore-Heir's power and toughness are
each equal to the number of Spore-Heir's
you control.
When you cast Spore-Heir, put a copy
of it onto the battlefield for each time it
was cast from the command zone.

* / *

==xx==

This is my goal, but I lose a lot of points for inelegance.
It's one more line than Prossh for reference.

When ~ enters the battlefield, if it was cast from the Command Zone, put a token onto the battlefield that's a copy of ~ except it isn't legendary. Repeat this process for each time it was cast from the Command Zone.
Creatures named ~ gain +X/+X, where X is equal to the number of creatures named ~ you control.

0/0

?

Hm. Not quite.

It misses the commander ruling. that's the important part, because copies of commanders aren't commanders (with the exception of a commander copying another commander).

The point is that you can better allocate commander damage.
Maybe do something slightly simpler.

Crown Spore --
Legendary Creature - Fungus (MR)

Each Fungus creature you control has power and toughness each equal to the number of Fungus creatures you control.
: Target Fungus you control becomes your commander until the end of turn.

* / *

==xx==

I switched it to Goglari colors, because a quick gatherer search revealed that besides green, black was the next highest color of fungi.

A Similar effect to making additional commanders can kind of be done like this:

Placeholder
Legendary Creature - Fungus Soldier
Other creatures you control have first strike.
Whenever a creature you control would deal combat damage to an opponent and Placeholder is unblocked, prevent that damage and Placeholder gets +X/+0 until end of turn, where X is the damage prevented this way.
2/5

Or if you wanted to be crazy
"~ is the source of all combat damage dealt to your opponents."

I like that, but I think it would be worded differently.
If another creature would deal combat damage to an opponent, [NAME] deals that much combat damage to that player instead.

What color would that be? It sounds kinda blue, a creature based hive mind per se, but already has a slight presence in green with the hydra that hits everyone.

Simic sounds good for that kind of ability. Though it might be too powerful as is.

Symbiosia --
Legendary Creature - Ooze (MR)

, : Choose X target creatures you control. Until the end of turn, whenever any of those creatures would deal combat damage to a player, Symbiosia deals that much combat damage to that player instead.

4 / 4

==xx==

And another fun one... could be a cycle of commanders.

Eloya, Blessing of Hope --
Legendary Enchantment Creature - God (MR)

Flying, vigilance
Bestow (X is the number of times Eloya was previously cast from the command zone.)
Enchanted creature gets +4/+4 and has flying, vigilance, and "If Eloya is your commander, this creature deals combat damage in the form of commander damage."

4 / 4

==xx==

Or even a commander "removal spell"

Command from Above --
Sorcery (R)

Target creature becomes its owner's commander. That creature remains its owner's commander as it moves to any zone.