It was the same misconception all Eternal Realm cultivators held until the Bastard arrived. The vast majority assumed they could no longer die no matter how severe the battle between the same realm.
They had proof enough of that and the issue was the Harmonic Core being out of place made their powers essentially subdued below any threshold to harm another in any meaningful way.
It also prevented helping without a massive consumption behind it.
Once the Harmonic Core was in place, a whole new plateau of power was made available. The aliens that Lind met had to have been well on their way to completing their Harmonic Core.
Lind had breezed past them because of his solid foundation and vast harmonic research. Combined with his harmony's essence, it made sense that he was able to quickly reach the peak of the Demi Tier.
