Guess My Card: A Quickdraw Design Game

[Zyardran]

Spoiler for Hidden:

idk, ><

[Aves]

Spoiler for Hidden:

[dragtom]

Aves got closest, guessing correctly that the cost depends on the number of opposing creatures.
although the incremental part was guessed correctly by silver.

[Aves]

Strength through Adversity.
Know thyself. Know thine enemy.
You have no time

[Zyardran]

Spoiler for Hidden:

[russianspy1234]

Spoiler for Hidden:

Meditation  5
Shield: Whenever a creature deals damage to you, generate a copy of that creature with 0HP.

[dragtom]

Spoiler for Hidden:

[Aves]

Russianspy1234 has the closest match to the prompt. Really cool idea, though we diverged a bit in the interpretation.
I like Discord's card the best as a standalone, very neat that poison can be used to mimic a growth effect.
However, dragtom gets the win! Successfully got the Stat buff to creature mechanic for it, though where he had it as part of the creature I had it in a spell.

Spoiler for Hidden:

[dragtom]

You'll become strong, my pet. With enough training, you'll become as strong as a dragon.
And I will train you enough. The more I apply a force to you, the stronger you become.
I will focus - I do not need to drain-  all the force I have training you.
And then, after I've trained you...
I will have only spend a small bit of the force I focused-
but that doesn't matter for you. You will proceed and destroy my enemies.

[AD TienzuStorm]

Spoiler for ha what even:

Chained up Gravy monster thing
6
0 | 6
Cannot attack
Forceful: Gains double attack when afflicted with Acceleration
: Free Chained up Gravity monster thing

[Aves]

Spoiler for Hidden:

[dragtom]

aves got it right that it is a buff.