This is very cool, I love seeing community kits designs! I like the lore behind Remnant but I would have some concerns around the abilities. Here's my quick feedback on them.
Passive - On damage is a interesting passive delivery but it does have some pitfalls. There is no counter play. As a player my goal it to damage an enemy but this passive punishes me for doing so and there isn't anything I can do to stop getting the debuff. This is also a very punishing debuff. Since damage can also be applied quite quickly there would have to be some internal cooldowns or rules around when the debuff is applied which could also be complicated to manage and understand as a player. Lastly with the debuff happening to the player dealing the damage it will be hard for Remnant to see the effect of his passive working. Who shot me? Do I know which player is now debuffed.
Tactical - This tactical could work but we did move away from Silence for a reason. It didn't really fit the Rev fantasy and it has issues of understanding how the silence affected the enemy. Did my silence hit? Did it actually do anything? Maybe their abilities were already on cooldown. So I think it being something more persistent could work but there would need good communication to Remnant when the silence is applied to an enemy.
Ultimate - Can friendly and enemies interact with this to get converted to this state? Is there still the counter play of destroying the totem? I kinda like this ability but I do see it suffering from the same problems the old totem had. It will still have the camping the death totem to kill them when they return issue. Also being forced into melee might deter players from using it if that's not a way they like to play. So it would be tricky to balance this to feel fair while still powerful.