User blog comment:B214/Volume 23 discussion blog/@comment-77.188.202.233-20170429150936/@comment-26821288-20170502205551

Then what might this mean, Mr. Anon?

"I immediately equipped my crimson armour. Let alone my ordinary Balance Breaker, after that Evil Dragon War, I could now also equip my [True Queen] form immediately."

Issei won't be able to equiq his [True Queen] form without mastering Triana. But guess what, he can! And with a little bit of logic, I can say with certainty, that Issei has mastered CxC.