MTG Salvation

Scooping can cause kingmaking even without denying triggers. I have seen games where player A can kill player B or C but would die on the counter swing. If Either B or C concede, it would leave player A safe to win the game.

One particular example that comes to mind is a game in which I was dead to a mesmeric orb on my next turn. I reanimated my whole graveyard and gave everything haste with the intent of killing the mill player before I untap. While going through my triggers, the mill player conceded. I may or may not have been able to kill the remaining player had I been forced to send most of my attackers towards the mill player but as soon as he conceded, the game was mine. It definitely felt like the 3rd player had been robbed of an opportunity.

I don't have a strong opinion on whether the rules should allow tactical scooping, but it definitely feels like poor sportsmanship to concede in a multiplayer game unless someone went infinite.

Genesis seems good. You can tutor it and him milling it just helps you. Then you can bring back anything he mills in the future. If you don't play 1v1, you can also try to be political and tutor things the Phenax player wants such as Acidic slime to deal with a 3rd player.

Teeg players often don't expect any board wipes while Teeg is out so they may over extend. Toxic Deluge and Cyclonic Rift come to mind. Creatures are unaffected so Massacre Wurm or something could also hurt. I'd advise spot removal to just kill Teeg right before you untap so you can play whatever you want during your turn, but I assume he runs a bunch of ways to protect himself from that.

A constant mana investment isn't an issue at all with infinite turns. I'll pay 10 for Isochron scepter with Mystical Tutor to get Beacon of Tomorrows with some extra card draw for infinite turns. Sure I spend all my mana on the combo, but I'll eventually draw more lands then use those to win. No one else will get another turn to disrupt me if they can't do it on the first loop.

Players should prepare for the worst and assume time magic will be imprinted so even if you wait till right before your turn to imprint, everyone still has 1 turn to kill the mirror or you. I think the issue with the card is that in meta's where people avoid combos, someone will still accidentally do something to strong for other players to deal with since the mirror just seems like a goodstuff card at first glance. In competitive metas, I wouldn't expect someone to ever have an upkeep with mirror in play.

I don't really have a strong opinion if it stays on the banlist or not though. I'd probably use it for infinite turns if it were legal.

fyi: Oblivion Ring doesn't target anything when it's on the stack so it actually won't be cheaper. Still, I think you're right that your commander will be a removal magnet (especially if your opponents learn that you are easily hitting that hard).

Jolrael's Favor is another instant speed trick that might keep your commander alive. Rancor won't be cheaper, but its such a good card. You won't regret running it.

Definitely an interesting commander though

Aren't you undoing some of your own work when you cast your commander? I'd either run less spot removal or more graveyard hate. Why waste a card taking out their creature if it's going to come back when you cast Crypt Champion? Nihil Spellbomb replaces itself and Faerie Macabre can be reanimated by Crypt Champion. Bojuka Bog can take the place of a swamp and Skullsnatcher lets you reuse ETB effects.

Dolono has good suggestions but remember that Crypt Champion is only black so Fists of the Demigod will only give +1/+1 and wither.

Inner-Flame Acolyte is a favorite of mine in my Crypt Champion deck. 8 damage they didn't see coming and it can be reanimated.

Lowland Oaf seems solid. Gives power and evasion and at the end of your turn, you'll just fling the goblin anyway.
Vulshok Morningstar, Copper Carapace, and Vulshok Gauntlets will all help ensure you have high power goblins to fling.
Fireball, Swirling Sandstorm, and Bloodfire Infusion are other solid board wipes.

edit: Runed Stalactite can make anything a goblin (lets you sacrifice your commander)

If you're trying to be a bit more aggressive while staying on theme, Helium Squirter can help you get through. Stonybrook Banneret and Vedalken Aethermage seem like a shoe-in. Deep Analysis or similar card draw can allow you to keep counters on creatures if you want so you can hit harder/block more easily. A Trinket Mage package might be worth it (Viridian Longbow, Seat of the Synod, Aether Spellbomb etc.) I haven't looked too closely at your curve, but you may want to look at transmute cards (Dizzy Spell, Muddle the Mixture, Drift of Phantasms). Any equipment is another option- Bonesplitter, Vulshok Morningstar, Vulshok Gauntlets and others. Hope this helps!

Possibility Storm may seem like a chaos card, but it really shuts down blue when they can't rely on on counterspells anymore. Leyline of Punishment may help against pillowfort. Citadel of Pain isn't as good without manaburn, but it may make people think twice about leaving mana open.

Viashino Slaughtermaster seems like a lot of fun. Nyx Weaver is likely a stronger commander for BG recursion. I'd be wary of the battlemages. In my experience, 3-color commanders are either build-around or goodstuff. It seems pretty tough to build around the battlemages and goodstuff can get kinda boring in pauper since the good stuff isn't so flashy. Good luck and welcome to an awesome sub-format!

I run a lot of instants that pump and give trample. Put an aura/equipment on him and swing. If they block, Wild Hunger for up to 6 extra damage trampling over the blocker, if not, save the combat trick. Bloodrush is solid as a combat trick or a creature if you cant use your commander. pacifism effects can ruin your day but you already run a lot of protection from the color of your choice stuff so you should be ok. Journey to Nowhere but no Oblivion Ring? Infect can be a decent backup win condition. Ogre Menial with trample can be deadly fast. I used to run cards like Auramancer, but I found them lacking. I run less auras and more instants that you though. You may also need sac effects as an emergency way of protecting your commander. Fling or Bloodfire Infusion can do that while dishing out a lot of damage if twinclaws is buffed up. This is just my experience but I hope it helps!

I have about 15 cards I take out of Azami to switch to Talrand if my opponent doesn't like combos. I just remove some wizards/combo pieces and replace them with card draw and counterspells. Most of the deck stays the same, but the wincon changes entirely.

Rakdos Charm can do a lot of damage to a token player and has 2 pretty good uses if there isn't a token player. I've killed a token player with Blood Artist triggers after a board wipe once too.

I've had whole decks of mainly proxies but they were underpowered compared to my real decks. My opponents were sick of playing against the same decks every time and I was happy to play something new, but I wasn't willing to spend a few hundred dollars every time my opponent complained that they were losing.

You might also want to consider changelings as slivers. You can reuse slivers with Urborg Uprising or Aphetto Dredging. I'd probably cut cards like Bone Splinters since you could have just sacced the creature to kill your target using your commander rather than waste a card in your hand. Undying Evil and Antler Skulkin might also help with letting you hit multiple things with a single sliver. Looks fun.