Elder Seed Artifacts!
These artifacts could be considered to be the pinnacle of immortal magic.
They were something Alephee's brother Aleph had created while he was at the peak of his divinity.
Aleph had lived countless lives through his incarnations and used his godly powers to perfection to create the Elder Seed Artifacts currently in existence. Alephee had seen her brother's experiences up close, even accompanying his incarnations to see the births of some of the Elder Seed Artifacts he had created while exploring myriad worlds across the boundless cosmos.
Of course, Alephee didn't doubt Eren's potential to reach Aleph's heights one day. But she didn't think the current Eren was even remotely qualified to dabble in something like creating the Elder Seed Artifacts.
