The return of the Fire dragon king and the sky dragon queen

Chapter 1

"Hey igneel, where're we going?" Natsu asks, riding on Igneel's back as they're flying through the sky.

"We're visiting an old friend of mine, the sky dragon queen, hopefully she'll be able to tell us why your flames are silver instead of the normal orange/yellow mix or the rare blue/white mix." Igneel responds.

"Wait, my flames aren't supposed to be silver? I thought they were." Natsu says, confused

"I'VE TOLD YOU SEVERAL TIMES THAT YOUR FLAMES ARE ODD, WERE YOU NOT PAYING ATTENTION?" Igneel shouts.

Natsu laughs nervously at this

"Maybe?"

Igneel just gives him a glare and growls quietly "Next time I tell you something, listen to me, or I'll beat it into your head, now shut up and wait until we get there"

Natsu nods at this before laying back and passing out, Igneel just sighs before speeding up

5 hours they finally arrive and Igneel unceremoniously launches Natsu from his back and into a tree

"GRANDEENY, I'M HERE!!!" Igneel shouts.

The gentle and caring sky dragon queen who, up till that time, had been training her adopted daughter, has the young girl stop and has her follow her to the clearing where Igneel had landed before speaking up

"Hello Igneel, I wasn't expecting you, do you need help with something?" She asks.

"Yeah, a few months ago I took in this brat," he points at Natsu, who was still sleeping soundly even though Igneel had launched him into a tree upon arriving, "and decided to start training him, but I noticed something odd about his flames"

"What would that be?"

"They emit a demonic presence and are entirely silver."

Grandeeny is shocked by this but doesn't show it, and after thinking for a few seconds, she uses her tail to point at her daughter, who had been hiding shyly behind her leg with her head poking out

"I noticed something odd about Wendy's wind as well, her wind is blue and emits an angelic presence, I'm guessing you're here in hopes that I can help you figure out why your son's flames are silver, so I will help you find out on the condition that you help me figure out why Wendy's wind is blue." She says.

"That is acceptable." Igneel says with a nod.

Igneel decided that they would stay there for as long as it took to figure out the oddities to the magic of the 2 children, it ended up taking 2 and a half years total, giving Natsu and Wendy plenty of time to get to know each other and grow close, the answer to Natsu's magic came when Natsu's older brother, who had given Natsu to Igneel to take care of in the first place came after a year to visit and revealed the answer to the 2 dragons in private while questioning how Natsu was doing the answer to Wendy's magic came a year and half later when Wendy's biological mother visited and revealed that she was, in fact, an angel and that Wendy was a half angel, her father being a human who she had fallen in love with, but he died and it was forbidden for living creatures, aside from full blooded angels or gods to enter heaven so she was forced to leave Wendy in the mortal world world in order to escort Wendy's father to heaven, and that was where Grandeeny had found the girl, the 2 dragons were forbidden from telling the children their origins or the answers to their odd magic, but they would have never gotten the chance to anyways, as the day Igneel and Natsu were planning to leave disaster struck

Natsu is saying his goodbyes to Wendy and promising to visit when suddenly a massive magical pressure appears coming in their direction, shocking and scaring the 2 dragonslayers, and causing the dragons to panic a little bit