Nutama, Pride of the Savannah

Legendary Creature - Cat

Vigilance

Landfall - Whenever a land enters under your control, gain 2 life and create a 1/1 white Cat creature token.

Whenever a Plains enters under your control, you may have Nutama fight target creature you don't control.

6/6

Make a Whale with Dredge or another graveyard mechanic

Emanator of Flames

Creature - Elemental Giant

When you cast Emanator of Flames, as it enters the battlefield, it deals damage equal to the number of mountains in play divided as you choose among any number of targets.

5/6

Basically the cycle would be the same idea but for each of the basic land types.

What makes them mythic is that the trigger happens AS they enter, not WHEN they enter.

It triggers on the stack as it resolves. This is a significantly tighter restriction and timing event.

Feel free to make another Emanator of XXXX, but the cycle is pretty self-explanatory.

Scry, gain life, make tokens +1/+1 counters, -1/-1 counters, lose life, etc etc etc

So, wild instead

Sphinx of Perplexing Temptations

Creature - Sphinx

Flying

Whenever one or more creatures attack you each turn, the next spell that player casts on their turn costs X less, where X is the number of creatures they attacked you with.

At the beginning of each players end step, if that player didn't attack you, they draw two cards.

4/4

I'm not sure what kind of a deck would want to run this as it incentives your opponent both to attack you as well as not to attack you.

But fun fact, since you can't attack yourself you'll always draw two cards during your own end step.

Make a card that would make this creature useful in an Esper Commander deck

Amex, God of Sleep

Legendary Creature - Cat God

Defender, shroud

During your turn, tapped permanents can't be untapped unless they are your permanents during your untap step.

3/7

I'm sure there's some way to abuse this but I can't think of it right now.

But sleepy cat is best cat.

Make another Cat God because why the heck not

Duplication Nexus

Legendary Artifact

Whenever a token enters the battlefield that wasn't created by Duplication Nexus, create a token copy of it.

After eons of research, Tezzeret finally achieved his goal: Perfection.

High cost because makes token copies of ANY token, not just yours.

Make a card about something you've recently learned

Lion Turtle

Legendary Creature - Spirit

Hexproof

At the beginning of your upkeep, if you control five of each basic land type you win the game.

10/10

That should work, I think? If you have 5 lands and cast Energybending, then all five lands gain all five basic land types.

Right?

Wild

The Dragon Turtle is a D&D monster.

I believe you mean Lion Turtle

Judge!

Sorcery

Put a nonofficial counter on target permanent. This counter stays with that card even as it changes zones. As long as the nonofficial counter remains on that card, it loses all typing and can't gain any.

"Juuuudgeeee! My opponent is trying to block with something that isn't a creature!"

Obviously this would be for an unset, and the implications for using it on a Commander are outrageous and wild.

Because while Commander isn't a "type", "legendary creature" most certainly is...

I always love taking challenges way to literal :3

The aurora borealis was visible in northern Illinois last night. I drove all the way to the edge of Wisconsin to see them.

Make a card for the aurora borealis.