Phoenix Logs/Banished Units/Voridus
From Halopedia, the Halo wiki
Voridus takes to the field an iatrochemically-enhanced armour powered by tanks of infusion gel. Voridus can drop this gel from his tanks, leaving long-lasting toxic energy pools in his wake which damage enemy units but which can be harnessed by his allies.
Though he takes to the field with a standard gravity hammer, once he acquires enough resources he replaces it with an Infused Hammer, which creates energy pools with each strike and synergizes with his armor. Voridus can also intentionally release gel from his tanks when he activates his Salt the Earth ability, leaving wide energy pools in his wake.