How many useless entropy cards are there though?
Its not so much that a card is useless in and of itself, but that it can become useless in certain situations.
For instance, if you were playing mono-aether and they had nothing but immortals and phase-dragons, it would make a lot of sense to start trading in antimatter and chaos seed cards in the hopes of getting creatures to fight back with.
If this card allowed trading in of cards from your hand and is made cheap enough to be splashed off of an
mark, it could very well be one of the most useful cards in the game. Essentially it lets you turn any card into a random different one. I.e. you can instantly adapt to counter strategies.
Some examples:
-You are playing a psion deck and your opponent pulls out a mirror shield
-You are playing a gravity deck against mono fire... you can trade in weight shield for something that might actually help
-You can put enchant artifact into any deck that uses earth just in case you fight
or
and trade them in when fighting other elements
-Put these into arena decks when the oracle gives you a shield card (I soooo wish I could do something like that on those days)
-Trade in Wings if fighting a deck that is heavy on flyers
-Trade in CC cards when fighting mono-aether
-Too many pillars and not enough cards to use them with?...
In summary:
-Allows situational cards to be included more easily since they can be traded in
-Allows decks to adapt when one of their cards is being countered
-May help make up for bad draws
I'd say thats pretty useful myself.