So while I do not contribute to the M:EM at this time, I do dabble in conceiving my own Magic: the Gathering fan material, including characters and stories. Considering I have a tendency to go pretty far in attempts to make unique characters, I also have a tendency to go TOO far beyond the realm of possibility when it comes to characters, especially planeswalkers. I'd appreciate some feedback on which of the following are too outlandish and which ones are somewhat reasonable.

A planeswalker who experiences either a time magic experiment failure, or Kozilek-esque distortion (recall the time Kozilek rewound a Zendikari into unbirth) causing him or her to relive a certain period of time (a la Groundhog Day) repeatedly, making different decisions each time, causing different experiences with magic, summoning different creatures, and experiencing different ways of life via different planar travels, until the timeloop is fixed.

A planeswalking lich (or necromancer on his way to becoming a lich) who creates a small number of phylacteries (out of unimportant items, esp those benefiting a mage, such as Charcoal Diamond or Jet Medallion ) While most believe any brush with death of this sort would snuff out a planeswalker's spark, in this case I more-so imagine it would more surely damage the spark, either weakening his ability to planeswalk, or simply removing his ability to planeswalk until 100% of his soul is recovered. If the latter, he would likely task another planeswalker(s) in taking his phylacteries to other worlds, essentially sacrificing his ability to planeswalk along with his ability to die permanently.

A sentient NON-Elder Dragon planeswalker, born of a Jund dragon, either laid as an egg and/or hatched with at least Bant/Esper's and/or mana affecting the intelligence of the dragon.

A Zendikari half-human half-elf having inherited a darker skin tone from her human parent (similar to Echo Mage ) and whom embraces the Totem magic familiar to Zendikar. Perhaps is also more easily able to access different colors of mana due to being fluent in the forming of mana bonds, at times to cast totems such as Crab Umbra

A Drow planeswalker (or a vague caricature of a Drow, such as a black-skinned white-haired elf) who lives (or comes to live) on Fiora and lives day-to-day beneath Paliano and endures Fiora's political intrigue and subtle backstabbing.

A half-Neurok half-Moriok planeswalker who comes to believe he is some sort of masterpiece, and aims to spread his greatness throughout the multiverse via polymorph magic.

A artificer who studies the different races across the multiverse and crafts masks and other artifacts used in an effort to better learn (and teach) of the lifestyles of these different races by the wearers taking the forms and other qualities of the respective race attributed to the mask or other artifact.

A planeswalking shapeshifter (no idea where from) who, upon his visit to Theros, either winds up in a storm made by Keranos which is designed to bring about Stormborn Oreads/Naiads and is struck by a bolt, infusing him with some of the powers of Nyx, or encounters an Arbiter of the Ideal and is affected in much the same way. This results in the shapeshifter gaining access to the thoughts and emotions of anyone or anything he takes the shape of, being a sort of blessing and a curse at once.

A human planeswalker who adheres to the theologies or present alternatives on each plane she visits, and is able to use mana to summon a construct of said mana to embody the brand of justice present on a given plane (for example: On Innistrad she can force an angel to come into existence with understanding of what Avacyn stands for, on Theros she could bring forth an Archon with knowledge of the gods, or even some sort of nyxborn or alseid in her dreams)

A human planeswalker and philomancer who primarily devotes his magic to love, its fundamentals, its manipulation, and its pursuit. This sometimes gets him into inappropriate situations, making him various friends, enemies, and scorned lovers. Primary difficulty is how philomancy can be used to defend oneself, or what types of and spells and creatures would be necessary as his secondary skill set to move him along through certain problems.

A human werewolf planeswalker who struggles with her lycanthropy on other planes, such as Shadowmoor (perpetual night means frequent full moons, Mirrodin's "suns" are also known as "moons" and nonetheless are concentrated celestial spheres of mana, the Atarka attempt to hunt and kill her in werewolf form to offer her to their dragonlord, etc) and practices culinomancy while she is in human form, using and magic to pick out non-poisonous and ripe ingredients, draw flavor to the surface, augment flavors and nutritional qualities, and to kill the beasts whose meat she selects, and to heat warm meals.

The time loop walker isn't a bad idea, if a little tropey, but you really shouldn't make the experience multiplanar. That causes way way way too many problems with timelines and just the sheer amount of power required to affect multiple worlds. We're talking "rip reality a new one" mending levels of mojo.

I can't really speak too much about the lich for various MEM reasons.

Dragons are sapient on many worlds, but Jund is not one. Trying to invent a reason for something different in addition to being a walker is stacking things a bit high. There are other choices, especially Dominaria, and what does being from Jund, but not a traditionally Jund dragon really provide? Plus, just generally a good idea to not make a walker from a canon world. If you want them there, just make it the first walk.

Nothing really bad about the aura mage in a vacuum.

You wouldn't have half breeds in Mirrodin. The metal isn't genetic, it's environmental. He would be what he is because of where he lives. Nothing to say he couldn't be multicolor, but it wouldn't be a shift in culture.

The artificer and shapeshifter feel like they're competing with each other a LOT. I don't really think there's enough space for both of them. Even then, it might be worth simplifying things for each of them.

I've tried playing with a cleric myself in the past. More so than anything, I think the character needs a little more grounding, some sort of motivation.

The last two, you know how there's been plenty of comments in the past over them.

Well, I had thought to make it multiplanar as the intended effect would only affect the planeswalker, and would cease, leaving all other events but one only in his mind. Even if not, to make it simpler I had considered it being less of actual events transpiring and being immediately rewritten, and more like some Inception-style dream sequence that merely does reflect actual actions he could take on a small number of planes.

Why exactly can't you speak for a lich? I have heard of a planeswalking lich in the M:EM, though I avoid looking too far into it or else risk copying. Heck, I'd even considered it being a former Oldwalker, but I feel Liliana's already been given that option. Not sure if a Black Oldwalker who merely took a route to "immortality" that Liliana refused would be stepping on the toes of canon or not. Not to mention the logistics, although Liliana's interaction with Bolas in a recent story heavily implies being a planeswalker and becoming a lich is possible, I can handle whichever effects the process would have on the lich's spark.

Well incorporating canon planes is one of the primary reason I'm wary of assimilating into the M:EM, but I do try my best not to involve my characters or potential stories into canon plotlines whenever possible (when they're not, I might wiggle a little such as a character I intend to seek aid from Pharika's followers, so some of a god's mojo might get involved, for example) Though in this case I'll admit it's an attempt to achieve a character who fits somewhere in a very similar skill set as Sarkhan, but it's difficult to do so without said character resembling a carbon copy of him, so a dragon planeswalker was the initial consideration, and I'll be honest, Dominaria is a very complicated world that I have little to no understanding or interest in. Tarkir dragons are unable to be planeswalkers (despite the notable exception in Ugin) and besides Ravnica's very own Niv-Mizzet, no other plane's dragons seem to have the potential for rational thought besides such an implausible example as the one above.

Oh, really? O.o So in this case, if 2 Neurok humans have a child in the Mephidross, it'll be a lead-encrusted Neurok, or a Moriok? If 2 Moriok parents have a child in/around the Quicksilver Sea, the child will be a silver-laden Moriok, or a Neurok? If it's the latter answer for both, then all I can imagine is to use the "born under the ___ sun" idea similar to Slobad's being born during the Blue Sun's Zenith (though even in his case, he still kept a Mono-Red identity) I rather enjoy Meren of Clan Nel Toth's portrayal of a Jund/Grixis split character, with her typical Jund magic manifesting in a manner more characteristic of Grixis magic.

I can see where you're coming from, though I do think they have their own identities, though unsure of what you might suggest would simplify their individual characteristics. One is a shapeshifter who essentially experiences his subjects' psyche and emotions as he spends time in their form, and the other is an artificer who also studies biomancy and weaves the two arts together to pass on the opportunity to unite peoples of different races through experience-based education. There is some overlap, no doubt, but I find there to be enough differences for them not to envelop one another conceptually.

Right, considering some of the promotional material made the concept of "On Theros, the gods there are REAL" seem a bit more pertinent than the block actually did. So I hoped to hold a visit to Theros til much later, so that did make me scratch my head as to how she would make her beginnings. Was she without belief? Did she place her belief in the wrong individual(s)/parties? Did she merely begin to question the validity of her world's divinity after discovering other worlds had their own? Though I haven't managed to put my finger on any single conclusion. I find it really interesting to see her unsure of what forces and divine/authoritative figures to devote herself to, so she attempts to convert as she moves from plane to plane, learning what she can to make an informed decision. Church of Avacyn here, Pantheon of Theros there, striving to achieve sigils and the believed angelic ascension, association with Boros/Azorius/Orzhov and adherence to the Guildpact (lol whoops, it's gone to Innistrad) the democratic clergy under a monarchy (currently no more) etc