Elenei began releasing her Frost-Fire at full force without holding anything back. Normally, such power would be capable of wiping out empires or maybe even a small continent, but Elenei wasn't externalizing her power.
The target of her Frost-Fire was actually her body. Of course, doing this couldn't significantly damage her, much less allow her to undergo Nirvana. This was a unique step in the process of undergoing Nirvana that Elenei came up with.
Ever since she was forced to leave home due to her unstable bloodlines and inability to progress any further in her cultivation, she's been thinking of ways to overcome this obstacle.
