I am adding lair actions to some of my boss fights in a gm campaign and using an invulnerable, invisible npc with the lair abilities so its in the initiative order.

What I need is a perma invis status since it becomes visible when even I use an ability.

Now this is just a QOL / immersion request since functionally it works and I just have to redo invisibility every turn or just have a super squirrel runing around.

Maybe an invulnerable nearly invisible llittle energy ball turned into an npc would work also.