The Stasis-sealed chest you unlocked contained an interesting piece of armor. Bring it to Variks so he can examine it for you.

Now that you understand how useful this power can be, you should keep an eye out for more Stasis Seals. By breaking them open, you can obtain valuable equipment and destabilize House Salvation even further.

It's time to demonstrate your newfound skills in a much more impactful way. The Exo Stranger mentioned the members of Eramis's dark council each hold their own Splinters of Darkness. Variks will know where to find them.