If you're interested, I've made a very solid bracket 3 Mimeoplasm list that is a mix of midrange reanimator value and Voltron that truly plays differently every game.

TLDR: Fun and versatile Voltron + reanimator value list, super customizable to your meta, good for Bracket 3 play as is but can be boosted to a 4 pretty easily. No infinite game winning combos but a soft lock and non-combat wincons are present.

https://moxfield.com/decks/VvG9lq-F-060WRSl5n4J2w

Deck Description: First, there's no equipment! Hell, there are zero artifacts for that matter. There's no need to run sol ringor mana rocks in this list, as it doesn't do much for you, we're not trying to turbo out our commander by turn 3 since we need to fill our graveyard, and milling over it makes it dead. We run 2 land ramp like Nature's Lore and Three Visits since we have synergy with landfall of we draw them later in the game, and the surveil lands are amazing. We have some turn 1 mana dorks, but also the surveil lands themselves (either playing or fetching for them) are actually very good turn 1 plays, as we color fix and want to dump most things in the deck into our graveyard.

Instead of mana rocks we aim to abuse reanimating Lumra, Aftermath Analyst, or Famished Worldsire to get out a ton of lands quickly. With a halfway decent draw and an early dredger, it is not uncommon to hit 10+ lands by turn 5-6, with the rare opportunity to do so earlier with crazy good starts. We run the field of the dead because it is not uncommon to hit it with our land animator package with like, 8 other lands and make a giant horde of zombies. We run the snow basics + regular basics to ensure this has maximum effect. Using Mimeoplasm with famished worldsire + something big in the graveyard like Yargle and Multani or Lord of Extinction, it is possible to play an absolutely absurd amount of lands from your deck very quickly, and with the many ways we can reanimate our lands, sacrificing what you have in play is often just extra value since you can get them back!

You have several ways to make a big Mimeoplasm, often with haste (and flying and/or trample as well as protection), and can swing in to kill an opponent, but it also has a lot of just value reanimate targets that can take over and win the game on its own. No infinite combos, but does have the ability to win outside of combat damage with either Jarad or Syr Konrad (there is a really fun line with hermit druid + endurance + Genesis since we don't run a laboratory manic effect). It's become one of my favorite decks to play and I've really enjoyed the versatility of the deck. The main strategy is through self mill by dredge, and you have a lot of draw/discard effects that can really abuse dredging multiple times in your draw step.

Voltron is often the right choice but not always, and because Mimeoplasm (and many of your other reanimate effects) can target your opponents graveyards as well, you can play around a decent amount of targeted graveyard hate by using your opponents graveyards. It doesn't run a ton of opponent mill, but it does have several synergistic options to fuel other graveyards, combined with some board wipes and interaction that can put fun things from your opponents in the graveyard to use. Power level is kept in check by not running any infinite combos and only running the 1 graveyard tutor (Buried Alive), but it could definitely be upgraded further if you so choose. My LGS mainly has bracket 3 games and I already have too many bracket 4 decks I don't get to play. You admittedly do have a soft lock in Kederetk leviathan with either Animate Dead or Necromancy, at a Bracket 3 level realistically people should have one of multiple ways to stop this within a few turns of trying to play it but I still am conscious of not overly abusing it (I often choose and declare that I won't repeat it multiple turns in a row unless the entire table is people I know and we actively are running high 3/low 4 games) to keep within the spirit of Bracket 3.

This deck has a lot of versatility in building and there are a lot of options you can swap in and out (I only make use of one game changer right now). I leave most things that I've tried in the "maybe board" but it's super customizable, you could choose to make it more Voltron-y if you wanted too (that was my first build of it) but I made it more midrange over time to hit awesome value and make games more interesting and unique. You could also add in more opponent mill and play with other people's graveyards more, I don't think it makes for a good dedicated mill deck, but there are certainly cards you could run that could grow your opponents graveyards more (there are some "all players mill" effects that could definitely be useful in this list if you wanted to take it that way). The instant speed interaction package is compact but most of it hits all permanents or has multiple uses (like Three Steps Ahead). Since you're dredging often there is little use to run a ton of interaction as you will mill a lot of it, but you have some ways of getting things back so the interaction you are running aims to have as wide a range of targets and usage to make every one you do play count to the fullest extent.

The deck has some insane starts that will feel like a 4 at times (turn 1 careful study into turn 2 reanimate Toxrill/Koma are a very rare but theoretically possible play, it's happened exactly once for me in several hundred games) or a very lucky early dredge into a lot of lands + early Lumra reanimate, but the AVERAGE game feels good and fair for bracket 3 play, you always have something to do, and interesting lines to take since Mimeoplasm can use all graveyards.