The teen certainly didn't have time to sulk about the match as her opponent started his first movements. Her adrenaline began pumping into her system and she could hear her own heartbeat in her ears as he raised his fist. Her hand would slip to the dagger at her back and grip its hilt with the odd gem. Now, she did not possess any specialized dōjutsu that everyone crutches themselves on so her reaction time was forced to be able to respond to such threats just as quickly as they. Unfortunately, that also meant she couldn't read chakra or handseals. But what she could rely on where her senses and female intuition. The next move would occur at the same time that his forearm opened up to fire the missiles. There's no retro-posting as she is still gonna fill acknowledge the missiles and the immediate threat they possess...
When his forearm opened up, she would, in one fluid movement, remove the dagger from its sheath and flick it at her opponent. Granted, the missiles would traverse much quicker than her dagger but she threw it with such uncanny accuracy that it would slice right through the space between each missile. But what's one little dagger in comparison to five rockets?! In defense of her life, her left hand would rise up and manifest a large ice wall (10 ft by 10 ft by 3ft) made up of hexagonal plates at the edge of her area of influence. This action was instaneous and would be able react to the dazzling celerity of the missiles and as such would prevent her any harm from the shrapnel or explosion that might occur from impact.
But, as her opponent said, the missiles would explode at 11ft and thus effectively run straight into her ice wall. Being a Yuki member's ice, it would suffer very little damage, only reducing the thickness by 1 and half. The gas, on the other hand, would have to flow around the wall to get to her being and she certainly wasn't going to allow that. She sprinted towards her ice wall, removing her trident from its strap, and just as the gas would begin to cascade down the wall, she would disappear into the ice. Her reflection would momentarily reflect over the entire surface before disappearing entirely. Now, back to the dagger! Remember how it's been noted that it carries an odd gem? Well, at this time, her opponent would surely be more focused on his actions being foiled as well not being able to perceive her actions with the Sharingan because of the reflective nature of her ice wall. The Byakugan might be able to see her movements but not be able to predict what would occur next.
Her reflection would momentarily appear in the small odd gem before her body would spawn forth at a lightning fast speed, her trident point first. With the range of the trident (6 ft) in length, she should find its point home in her opponent's chest, just to the right of his sternum. Coupled with the speed of her assault and the momentum of the thrown dagger, the impact would be strong enough to crush his ribcage and tear right through his heart and left lung.
Throw dagger
Hyōshīrudo no Jutsu (Ice Shield Technique)
Makyō Hyōshō (Demonic Mirroring Ice Crystals) variant