The spirit energy weapon that Simoke hasn't unveiled is forged specifically against the Dragon Soul. It may not kill Anfa, but it will undoubtedly injure her severely, forcing Anfa to recuperate for half a year and miss the upcoming exploration action of the Exotic Species Research Institute.
Of course, if it were an ordinary Sublimator, facing this weapon would mean certain death, not even a chance to recuperate... This is because Anfa's Dragon Soul is not complete. For Sio, even if captured by Avak's laboratory, she wouldn't have suffered any irreversible essential damage.
This was evident from the group's earlier reactions, where only Sio's response was the calmest—despite Ian having third energy level strength and having solidified his soul through meditation, he instinctively took a defensive stance, sensing a threat to his life, but the Dragon Maiden simply furrowed her brow, suspecting the matter was not straightforward.