Personally, I think the upgraded should not restrict the effect to one player - but I'm rather a fan of cards like Nightfall that can benefit both players. (In fact, 3 of 4 cards I've invented have this property!)
If I have 5
and 5
and I play a creature that costs 6
, what will happen? Will I either
A)lose 5
and 1 ![Light :light](https://elementscommunity.org/forum/Smileys/solosmileys/../../../images/Misc/light18x18.png)
B)Lose 3
and 3
, or
C)Lose a random amount of both until it =6?
The only situation where this would matter is if the card gets destroyed or (upped only) stolen. PA removes the question entirely.
![Smiley :)](https://elementscommunity.org/forum/Smileys/solosmileys/smiley.gif)
IF this card gets implemented, the elements should be placed directly opposite each other in the game window. Right now we have Time next to Light, Darkness next to Water, etc. - it would be a lot less confusing with matched pairs.
I'm not sure about this being OP in Rainbows. It takes a minute to set up, and a lot of rainbows rely on cards from both in a set of opposites - Firestorm/Permafrost, Druid/Oty, Steal/Sundial. Without a really good pillar start, the cost will cancel out a lot of the setup-speed benefit gained. In a rainbow vs mono/duo match, mono/duo will have a speed advantage as always, I don't see this getting around that. Rainbow vs Rainbow matches are one reason I'm in favor of having both versions of the card affect both players - otherwise a ton of rainbow decks would automatically have to include this for the slight eventual advantage it grants.