Another Child of Hades?

The Attack

We heard the sound that meant we were under attack. We grabbed our weapons and ran to the barrier.
'We noticed that is was a group of empousa, many cyclops, and some cheerleader demons, which I can't remember the name of.
'We were gonna wait a month, but our boss changed his mind. Hope your ready!!' Kelli says with a evil cackle.
'I know what to do.' I say
'Let me use my powers. All at once.'
'That is really dangerous, but if you think you can get them all in one shot, go for it.'
I control the water from the lake to form a shield around the monsters and me. I create some lightning and added it to some left over water, then I added the breath of death to the mixture and the underworld's pain from the fields of punishment. And spread it among all the monsters. It killed them all, and gave them a very painful death. All that was left was the pit, but he wasn't here. I assumed he'd be here soon. I started to feel dizzy, but stood my ground. I waited. I started to feel the ground shake, Nico and Percy have joined my side. Just as the pit arrived.
'Where's my army?' He asks
'Dead.' Percy responds for me, looking at me worriedly, noticing I am not feeling well.
'He looked shocked, as he noticed the shield around us.
'Who killed them all?'
'Crystal.'
'Who?'
'Me, I've been in you three times, and you still don't recognize me?' I said looking up. 'Let's end this.' Says Nico.
We get into fighting stances. And pull out our weapons. My swords start to glow. Tartarus looks at them in fear. We charge at him. Percy takes the left, Nico right, and I got center. Nico goes down first, not dead, but unconcious, I allow a son of Apollo to take him to the infirmary. Percy starts to glow a faint red, and fits harder, but Tartarus is matching us blow for blow. I start to use both swords, since I only used one to strick. Then I see Percy go down. Now I'm glowing red, for my brother and friend. After 15 minutes of slashing and dodging, I see and opening in his defense. I rush all of my powers towards that spot and thrust my swords in it. He slowly turns to dust, going back to the underworld. He manged to throw a knife at me, and it hit my stomach. I hate my ADHD. With that he turned to dust. The prophecy is complete, but I only see black.