So now it disappeared and I couldn't ever use it. Now forced to wait the week cooldown for war because of this glitch. I even tried it after my group registered this morning. Same Chinese error that I have no idea what it says. RIP.

Upon using the Item, it'll disappear after a week.(From when it was obtained prior to the second merger event)

The Chinese message informs the player that the item has been used and your CD has been refreshed.

However, thank you for reporting it!