Israfel, can not upgrade

hopeslight

i have tryed to upgrade the speed of my Israfel, and it will not alow me to do so, it does not ever recognise i have one, when i goto the arogear forge. i receved this flyer as a trade with someone else, and i was told you could upgrade it, and not i can not, i really do not want to have to go buy a new one, and end up **** someone else over and them not being able to upgrade it.. please tell me if ,, i assume this one is a event one, there upgrade able, and if not, why, you now sell them in the cash shop. and should be upgradeable, and if you do not plan on making them upgradeable, then you shald at the very least chage them somehow, so that who ever is buying them, KNEW that they can not be upgraded, like in a tool yip. when hovering over it in your invtory, it will SAY not upgradable. that way ppl. will know and not get screwed over...