I think something totally strange and random would fit entropy,
Possible Suggestion,
Chaos Monolith
Each turn
is generated. Chaos Shift : When Chaos Monolith comes in to play, all creatures swap stats and skills with each other.
When this card is played it causes all creatures to change their stats and abilities into another one in the same side of the field. It's effects can range from something harmless to sometimes useful or can even be against the caster himself (So it is a gamble).
Example : Imagine that opponent has a Skeleton, Bone Dragon and Armagio. Player summons Chaos Monolith into play. It swapped the creatures stats and abilities into the following :
Skeleton - 1|5 with Gravity Pull. (Armagio's attack, Bone Dragon's hp and Armagio's ability)
Bone Dragon - 1|25 (Skeleton's attack, Armagio's hp and Skeleton's Undead ability)
Armagio - 10|1 (Bone Dragon's attack, Skeletons hp)
It can be very fun card with usually mild effects and sometimes useful. Here, Gravity pull has become useless for the opponent and the Dragon becomes more vulnerable to CC. This card would create wide range of different situations in a game. The main thing to note is that overall damage output of the players still remain same so i think it is a pretty balanced effect for a cheap monolith effect.
What do you think ?