It would be great to distinguish between each blade we have circling over our heads during a match. With treasure card blades, blades from gear, using Sharpen Blade to boost a regular blade, it's hard to remember each enhanced, regular, gear, or treasure card blade circling over head. My suggestion is have a different color ring around each type of blade that can be used. That way we're not using the same blade by accident. It's kind of upsetting thinking i have 6 blades to attack a boss with and only end up using 4 because i had 2 of the same blade over head.
If you put your mouse under that... brown colored piece of paper thingy with our name on it in the duel circle, it does that for you! At the moment all I can remember is that treasure card items are yellow, and I think regular cards are blue or purple... I forgot the details but just test it ingame and it should be very easy to learn