Rules: Describe aspects of a card without revealing its name, so other players can guess what card you’re thinking of!
Example:
My favorite day is an unlucky Friday.
My favorite movie is In the Shadow of the Moon
I like telling you that you can’t do things.
Pastafarians adore me.
Who am I?
Emrakul?
haha quite possibly! You want to make one up? 
Here’s one:
You’ll see me at the helm of a ship ready to destroy it all.
Oh, and I’ve given myself irreparable brain damage from watching that Tranformers movie with Mark Whalberg in it 10 times.
Who am I?
is it Skysovereign a.k.a. boomship?
I think I’m more than a pile of junk.
Most planeswalkers disagree with the first statement.
Sometimes I like to pretend I’m a dragon or a dinosaur
I’m really lazy, and only move when something momentous happens.
I float up with my boys
and shut down you and all your toys
and whenever more of my friends drop by
I stop you again.
Wait, am I a bad guy?
Kari Zev?
Never was I a thief,
but ever the snitch.
Should you come to end me.
I will add the scent of our deaths
to my crumbling home.
Trashos…
And no, not boomship or Kari.
Yahenni?
That’s definitely your favorite Mythic in DOM, right?
Nope.
Drowned of Hope!
Angrath?
Nope… Maybe not the easiest. Read the lines carefully. Some is a reference to a clue…
only the super bestest most awesome mythic ever!!!
jumps off a cliff
well you got mine at least
WAIT…it’s squee isn’t it? But he kinda came with brain damage
So part of the riddle is a red herring? I honestly have no idea… helm leads me to believe its lannery or brass. the second part of the riddle throws me completely off track.
@Mburn7 hint: wordplay on “Snitch”
is it that masterpiece helm from Kaladesh? Champion’s helm was its name I think. Brain keeps autopiloting to helm of Kaldra but I know that’s not in this game…yet.