Five commanders

[JovialJovian]

I have this notion to make a commander for each possible color combination. Here are the five 1-color combinations.

Michel, Fallen Shepherd 3WW
Legendary Creature - Spirit
At the beginning of your end step, return to the battlefield a creature card with the lowest converted mana cost among creature cards in your graveyard.
WW, Exile a creature card from your graveyard: Create a 1/1 white Spirit creature token with flying.
3/3

Fragment of Time UUUUU
Legendary Artifact Creature - Weird
Flash
Phased out permanents you own don't phase in during your untap step.
U: Another target permanent you control phases out.
When ~ leaves the battlefield, draw a card for each phased out permanent you control.
UU, Exile ~: Take an extra turn after this one.
5/5

Grobul, the Cystic Hulk 6B
Legendary Creature - Giant Horror
Wither
Whenever a creature dies, if it had any -1/-1 counters on it, create an X/X green Ooze creature token, where X is the number of -1/-1 counters on that creature.
B, Sacrifice a creature: Put a -1/-1 counter on each other non-Ooze creature.
6/6

Duke Barrington III 1RR
Legendary Creature - Human Noble
Whenever ~ attacks or a creature attacks you, create a Treasure token.
T, Sacrifice a Treasure: Choose one -
- Goad target creature.
- ~ deals 2 damage to any target.
- Untap ~.
1/4

The Quaking Weald
Legendary Land - Forest
You may play an additional land on each of your turns.
Spells you cast cost 1 more to cast.
XG: Each land you control becomes an X/X creature until end of turn, they're still lands.
~ can be your commander.

[Mookie]

Michel, Fallen Shepherd - this card looks fantastic. May be a bit too efficient (Meren of Clan Nel Toth requires some setup before reanimation, while Sheoldred, Whispering One and Reya Dawnbringer require you to wait until your upkeep), but I like the design a lot. Most recent white cards prefer to reanimate small things (Sun Titan, Reveillark, Rally the Ancestors, etc), so there may be concerns about reanimating bigger things, but I think this is a cool way to handle it.

Fragment of Time - the mana cost bugs me a bit, just because quad-color costs are so rare, and quintuple-color costs are almost unheard of. Just think of those poor, innocent limited players with no fixing! Still, it's an interesting (if very Weird) card. Not sure how I would feel about an extra turn in the command zone though.

Grobul, the Cystic Hulk - very cool design. Not sure if it would result in a fun play pattern though - seems like it would often go along the lines of 'sacrifice a creature, kill all the small things, make an army of oozes, sacrifice oozes to kill everything else', which makes it pretty much impossible for anyone else to play creatures. One option may be to limit it like Carnifex Demon (limited number of activations), or Pestilence (dies if no non-ooze creatures remain).

Duke Barrington III - looks very nice as an alternative to Captain Lannery Storm. There is some anti-synergy between goad and triggering on a creature attacking you, but I think it would actually result in a more fun play pattern. The last option looks very weird though - tap the Duke and sacrifice a treasure to untap the Duke? This seems pointless.

The Quaking Weald - you may want to add reminder text letting people know it taps for mana. Other than that, seems interesting. Hard to evaluate powerwise - Exploration in the command zone seems sort of broken, but increasing the cost of your spells may balance things out enough. The fact that you can fetch it with fetchlands and other land tutors gives it a lot of other implications - might be too powerful for Lands in Legacy, for example.

Overall: these cards look pretty sweet! Interesting to think about what sort of decks they would allow.

[void_nothing]

Great concepts all around.

Michel is fine - ripe for combos, but there are more efficient ways to reanimate one huge creature.

Fragment of Time looks like bizarre fun, but that activated ability needs a "you can't activate this during an extra turn" clause or else getting infinite blue mana = infinite turns, from the command zone.

I really like Grobul (quite flavorful and gross) and the Duke. The latter in particular is an interesting side of red, although the last mode of the activated ability is confusing; it seems like it's only there to enable some very specific combos as it's not really useful for anything but sacrificing artifacts for free and getting a bunch of taps and untaps.

The Quaking Weald is very innovative but dangerous. A fetchable free Exploration feels ripe for abuse even with a drawback. I also want to point out that as written, "commander tax" simply wouldn't apply to a land commander, although if such a thing were ever printed I think the rule would get rewritten or added to real quick.

[JovialJovian]

Oh, that's what I get for making edits on the fly, Barrington's untap mode was actually supposed to allow re-use of the tap ability, not be part of it.

Also, I should probably change Grobul to "Sacrifice a non-ooze creature:" and/or "Whenever a non-ooze creature dies..." to prevent it from just being a neverending, slow boardwipe.