Heart of Twin Stars Mental Cleansing

Heart of Twin Stars is utterly simple in its concept: you must divide your core in two. Thus, even when one core is disabled through some device such as my rival’s, you have a second to rely upon.

Unsouled (Cradle Book 1) - Originally HotS was a technique to split one's soul

He needed a technique that worked inside of himself, filtering and separating madra. That would be a spirit Enforcer technique, and he had started looking through the Arelius technique library before an idea occurred to him.
He had a technique like that.
The Heart of Twin Stars.
It had been designed to split one core into two, but it was a spirit Enforcer technique compatible with pure madra. With a few modifications, he and Dross were sure they could get it to work.

Wintersteel (Cradle Book 8) But its later developed into something that can split and filter more things, like different forms of energy

He drained power from the man, cycling the Heart of Twin Stars as he did so.
A rush of different energies flowed into Lindon, and he and Dross separated them together, processing them according to the Heart of Twin Stars. But unlike when Lindon had tested this on Remnants and dreadbeasts, this influx hit him like a runaway horse.
The priest convulsed and fell backwards, and Lindon let him go. It was taking all his mind and spirit to control the technique.
Soulfire and pure madra streamed into his spirit, blood essence suffused his body, and yellow-and-brown madra vented from his arm. The earth around him shook in response, but by far the most disturbing were the memories.
For a moment, Lindon’s point of view doubled. He was standing over the priest and he was lying on the ground, wondering what the young Underlord had done to him.
He wished his son was safe, dreamed that the treasures unearthed by the Dreadgod would be enough to take him to Overlord, and wondered when he could go home.
Then he realized he was in an unfamiliar body. It was taller, broader, younger, with pure madra flowing powerfully through it and the arm of a Remnant. Pure madra didn’t respond to any of his cycling techniques⁠—
[Whoops, hang on. I was supposed to handle the memories, wasn’t I? I’ll filter them and give you what you need to know, that’s my fault.]
Suddenly Lindon remembered who he was again—but he struggled to control his own body. Someone else was moving his madra, trying to move it in a pattern that would never work for the Path of Twin Stars.It was as though he’d pulled the man’s Remnant into his body.
But now that he remembered himself, Lindon put an end to that immediately.
He crushed the remaining will with his own, flexing his fingers to prove to himself that he was back in his own body.

Wintersteel (Cradle Book 8) And this filtering works even on thoughts and memories. The will part isn't part of it, but Ciel's gotta do SOME work

[In all simulations, it eliminates the parasitic technique. The time required ranges between eighteen seconds and roughly nine minutes.]
“Do we have the required materials on hand?”
[The Silent King threatened six beings besides the two of us. Your three surviving relatives, Yerin, Orthos, and Mercy. If that is all we need, and we are willing to accept a lapse in performance, then we have the materials on hand. Also, this assumes that we do not need protection ourselves.]
“We’ll be safe,” Lindon said.
...
Lindon could have assembled this construct in two seconds using his madra control alone, but he gave it his full attention. A dream Ruler binding and a purified soul Enforcer binding—one that he’d made to simulate the Heart of Twin Stars—went down first, and he fused them together with one strike of Genesis. He used the blue head, channeling pure madra, as this was a purification construct and not a weapon. The construct formed in moments, infused with power from his will, his madra, and this place. When he bathed it in his own quicksilver soulfire, it ended up pink and pale blue instead of the purple-and-white of Dross’ example, but a quick spiritual scan confirmed that it would work.

Dreadgod (Cradle Book 11) - Constructs made using the Heart of Twin Stars as a basis can eliminate the Silent King's TP parasite from its users

He devoured the Archlord-level sword Remnant in an instant, sorting its powers with the Heart of Twin Stars. The portion of its madra he could purify went to his core, its soulfire went to his own stores, its blood essence went to his body, and its dream aura went to Dross.
...
In her spare time, Charity harvested the minds and wills of Remnants, molding their essences together into a sort of construct. It had many uses, from bringing specially made vessels to life to attacking spirits from the inside.
The technique was called Sculpt the Soul, and the resulting product a Silver Heart.
Now her Silver Heart pulsed within Min Shuei, attacking the Dreadgod power binding her. Together, the wills of two Sages clashed against the technique of the Silent King.
The halo flickered. The Winter Sage’s eyes began to clear.
Someone came down on them from above.
On the back of a Thousand-Mile Cloud, Lindon swooped down like a diving hawk. He seized Min Shuei’s halo in his right hand before it could disappear and Consumed it.
The technique was devoured in seconds. He clenched his fist and revolved his Heart of Twin Stars, cycling the power.
Couldn’t he have done that sooner? Charity thought to herself.

Dreadgod (Cradle Book 11) - Similarly we see Lindon purify said parasitic TP technique using the HoTS after absorbing it