Claiming Another Life?

The other two powerhouses who formed the formation instantly retreated when they saw the crack in their Deadly Poisonous Triangle Formation. However, before they could retreat fully, they saw that their powerhouse died by having his head crushed to death by that person's hand that was like a dragon's claw before the headless body disappeared from mid-air, probably ending up in that person's spatial ring.

Their scalps turned numb as they arrived within their ranks, making not only them but all of them wonder who exactly was this person they had never heard of! From what they could see, blonde hair and sapphire eyes, he was probably an Alstreim, so it was unthinkable for them for this person to possess such power.

Even the soul of their fellow brethren didn't seem to have escaped, being crushed along with his poor head!

The people below were all in disbelief. It was an instakill like what Dragon Queen Isabella had done.

How did these two attain such power?