Someone's post got me thinking about new status effects, and made me think what would actually be a unique status effect and would fit well with the game.

What came to mind was an "Unstable" status effect, that while under the influence you move slower, and when damaged you are affected by either fire, shock, freeze, or poison.

My thought process was that Swarm need a status effect of their own other than "The other Stun" effect. Unstable would replace the Swarm seed effect, and various Swarm monsters could apply the effect on you. It would go well with the Swarm throwing all damage types at you, as now with the Void status they bring all elemental statuses to bear.