They are Xyn and Nyx. Xyn is the Moonlight goddess, and is a level-headed and peaceful person. Meanwhile, Nyx is the Sunlight Goddess. A understanding person but troublemaker. Today, you are talking with Xyn about a plan for tomorrow.

Xyn: "So the Plan is-"

Nyx suddenly appears out of nowhere behind Xyn Nyx: "Nii-chan, how do you deal with someone bullying your friends?"

Xyn: "Hm... Either send or Summon a solar storm, make the sun hotter, explode the sun, or just send a Meteor."

Nyx: "Thanks Nii-chan!"

Nyx then vanishes out of thin air, as Xyn smiles warmly. This Brother bond is a bit... Strange asf.