At this point all we know about Momin is that liked creating stuff, and ultimately built an engine/weapon that could not only decimate entire cities, but actually freeze them forever in time just as everyone was dying.
Although Vader did resist the mask's attempt at possessing him, so there's that. /shrug
__________________
"I am tired of Earth. These people.
I am tired of being caught in the tangle of their lives."
The mask seems to be Momin himself -- his very essence. Those who wear it become Momin's vessel. Vader resisted it fairly easily.
The lightsabers of Atrius resonated with his anger/rage -- corrupting those who wielded them. They clouded Vader's senses and sent him into heightened levels of berserker rage, just like everyone else who brandished them.
As far as relics go, the sabers are definitely more potent than the mask.
__________________
"I am tired of Earth. These people.
I am tired of being caught in the tangle of their lives."
It is unknown if he amped these lightsabers in any way, but the way I see it, the guy who uses those blades that corrupted Vader is more powerful than the guy who’s very essence couldn’t crack Vader.
Atrius' lightsabers resonated with the hate/rage he channeled through them when he killed his enemies: https://i.imgur.com/Tq5gUkq.jpg
That's what caused those who wielded the sabers to become 'possessed' and enter a hyper-bloodlust-mode. We have no reason to suspect they were 'amped' beyond that, however.
__________________
"I am tired of Earth. These people.
I am tired of being caught in the tangle of their lives."
__________________ RealistRacism: "Sheevites, much like the Banites, were meant to increase in power with each member. From Lightsnake to Gideon to Azronger, this was supposed to be the case. However, knowledge must've been lost in some kind of Gravid-like incident, as Az turned out to be a mid-tier debater with a sub-par track record, sh!itting all over Tempest's legacy. Sad."