After 'nicely' asking a priest for directions for her search, Eir find that the Power stone was kept in a tample deep under the sea which would come to surface only once in few centuries.
As she had the experience on Sea diving from before too, Eir easily found the place and entered the temple.
With her durable body, it wasn't difficult for her to endure those hidden trapped, but it actually hurt her pride as she stumble on them about a dozen times total.
Controlling herself not to bow up the temple whole she finally got in the chamber where power stone was kept behind a energy barrier.
She just pass her hand through the barrier and grabbed the stone. It was as easy as dipping your hand in hot bathing water. At least for her as anyone else would have melted outright just by touching the barrier.
She squeezed the sphere container and easily get the power stone from it after outright destroying the container with a bit of effort.
Now she had a purple stone floating in the air and producing flame all around as if angry after it's 'home' was destroyed by Eir.
She grabbed the stone in her hands but surprisingly even her body was taking damage even if just a little bit. It wasn't anything that would caused her any trouble though as she was the Goddess of Life and Healing was her speciality.
She tossed the power stone inside her Spacial storage but the space inside became quite unstable with all these infinity stones inside it.
Eir understood that she won't be able to supress the stones energy in this way anymore.
So she finally plan to create a device akin to Infinity gauntlet that could harness and stabilise the power of all infinity stones.
As she was a delicate lady, she didn't plan on making the same gauntlet as it really didn't suit her image.
Maybe she should create a necklace or bracelet for herself with these expensive jewels. But after thinking about it for a moment, she had a better idea.
She should create a beautiful sword with these stones. It will be the most powerful weapon to exist till now as with a single swing, she would be able to destroy start systems. She could even kill those Celestials that are too high for to reach otherwise. It will be called something cool like 'Infinity Sword'. Sound great, right. Then she will... ...
After daydreaming this and that and some creepy laughing, Eir came back to her senses again. She created a spell to stabilize the power stone trmpererly, then made her way out side. On her way out she 'accidently' lost control of the Power stone and 'unintentionally' transforms the temple into ruins.
Now then, even if it was just her daydreaming, she actually have to create that sword so she could safely collect all other infinity stones.
That's why she teleported inside Starblade, her spaceship and then choose her next destination, Nidavellir.