The shattering of the Dragon-Phoenix Seals relied on battle prowess. Essentially, the stronger you were relative to your cultivation, the more seals you could shatter.
Under these circumstances, Dyon had been capable of shattering all 11 soul seals the moment he awoke from his forgotten night of passion with Jade's elder self. However, it was very obvious why he couldn't do so – his body simply wouldn't be able to handle it.
However, for the first time, Dyon's soul, qi, and body were almost perfectly in line. His qi had reached the pseudo-dao realm, his body had entered the dao realm, and his soul was still sitting at the very beginning of the dao realm, having been forcibly suppressed by Dyon for so long. For a man who was so used to his soul vastly outpacing his other two paths, even to the point where there was a time his soul had entered the celestial realm while his qi was still of the essence gathering realm, this was a novel situation for Dyon…