ehhhhhh. it really shouldn't be immaterial imo... ignoring everything else, that really doesn't fit with the other category at all.
The idea is comes from the characters that make up the Chines [and Japanese] word for Contradiction. The Halberd and the Shield. Essentially it's on how there is a halberd that could pierce any shield and a shield that could block any attack. Obviously those would conflict.
The shield had to be indestructable in any other case except for when in came in contact with the Halberd. But considering that these are ideas, I expanded it to imamterial weapons. Gives EA some use.
The thing is not that it should be an Other card [with
![Rainbow :rainbow](https://elementscommunity.org/forum/Smileys/solosmileys/../../../images/Misc/rainbow18x18.png)
cost], but that it costs that much of a single element. Also, I can't tell where else it should fit.