Void Cascade is an endless game mode on the Zariman tileset that sees the Tenno purge and defend Exoliser devices that counteract the growing Void corruption. Mission control is provided by Quinn. This game mode is only used on a single mission node: Tuvul Commons, Zariman. Like all Zariman missions, it can only be accessed after completing the Angels of the Zariman quest.
When the Tenno loads into the mission, they will be waypointed to an Exoliser, which is a deployed device to reduce Void contamination. A swirl of Void corruption has grown on the Exoliser, and small tears in reality are emitting streams of Void energy that envelop the unit. The Exoliser is surrounded by a bubble that forces the Tenno out of their warframe, like an Orphix field.
The Tenno must use their Amp to destroy the Void tears. Upon doing so, the Void energy surrounding the Exoliser will turn red, and a ghostly, skeletal figure can be seen hovering above it. This "Void manifestation" must also be shot with the Amp. Once its health is depleted, the Exoliser will be free from Void corruption and will glow yellow as it cleanses the nearby environment of contamination, and the Transference-blocking field will collapse. The Void manifestation will resolve into a physical unit – a Thrax Centurion, a strange but intimidating warrior reminiscent of the Grineer. It will attack the Tenno. Other enemies – Kuva Grineer or Juno Corpus – will also arrive and attack the Tenno.
A meter will appear on the HUD, showing the level of Void Cascade as a red bar, increasing from left to right. The cleansed Exoliser will be shown as a yellow diamond on the right of the meter, and its presence will shrink the red bar, indicating that the Cascade is weakening. A timer will indicate when a new Exoliser will be deployed. New Exolisers spawn already possessed, and are shown as red diamonds on the left of the Cascade meter. As new possessed Exolisers spawn, they must be cleansed in the same manner as the first, using the Tenno's Amp. If there are more possessed Exolisers than cleansed Exolisers, the red bar will grow and the Cascade will intensify. If there are equal numbers of cleansed and possessed Exolisers, the meter will not move.
Cleansed Exolisers have a lifespan, and it will tick down, shown on the HUD meter and the Exoliser's waypoint. Killing enemies near the Exoliser (the area visualised as a bubble of yellow energy) will allow the Exoliser to harvest their essence and speed up its work. Once a cleansed Exoliser has expired, it will disappear from the map and from the Cascade meter, and will no longer contribute towards minimising the Cascade. The HUD will track how many Exolisers have successfully retired.
New Thrax units will also appear periodically, and they will head towards cleansed Exolisers. When nearby, they will attempt to possess it again. They must be distracted or killed to prevent Exolisers from being re-possessed and keep the Cascade meter low. Every 4 Exolisers retired constitutes a "round" of Void Cascade, producing a mission reward. If the Cascade meter ever fills completely, then all Exolisers will vanish. If at least one round has been successfully completed, then extraction will be waypointed; otherwise, the mission will fail.
(Grineer) "Grineer meddling with the Reliquary Drive has triggered a Void Cascade. Purge our Exolisers and keep them purged, so they can stop the Cascade getting out of hand."
(Corpus) "The Corpus have triggered the deployment of Thrax-possessed Exolisers. Deployed all together, they will cause an instant Void Cascade. I can stagger their deployment, give you time to purge them, so they can cleanse the ship instead of corrupting it."
(upon approaching Exoliser) "That Possessed Exoliser is spitting out contamination. Use your Void power to purge it!"
(upon cleansing Exoliser) "Oh, that got their attention. Enemy forces moving to your location."
Subsequent Possessed Exoliser spawning
"The enemy has triggered the release of a Possessed Exoliser. Purge it before it pumps out even more Void Contamination."
"Possessed Exoliser located. Purge it and make it work for us."
"Marking a Possessed Exoliser. Deal with it while you still can."
"Now the Exoliser's purged, any casualties you inflict within its field will bring the contamination level down."
"Any nearby attackers will degrade the Exoliser's performance. Clear them out to get the system working full-steam."
"Keep any roaming Thrax away from that Exoliser until it discharges. That'll nip this Cascade in the bud."
"Exoliser is ours."
"That Exoliser is working for us now."
When a Thrax is attacking an Exoliser
"Exoliser succumbing to Void possession."
"Exoliser under assault."
"Those Void nightmares are hellbent on one thing: manifesting more nightmares."
"A Void manifestation is possessing an Exoliser. Stop it before it feeds the cascade."
"Keep those manifestations away from the Exolisers."
When a Thrax successfully possesses an Exoliser
"We just lost an Exoliser to possession. Get it back."
"Exoliser suppressed. Purge it before it makes the contamination worse."
Cascade meter decreasing
"Void Cascade losing steam."
"Void contamination dropping."
Cascade meter increasing
"This cascade is growing out of control."
"Contamination levels going in the wrong direction."
(when Cascade meter is 60 seconds from maximum) "Cascade is approaching critical levels. Your time is running out."
(when Cascade meter is 30 seconds from maximum) "Void Cascade is nearing the tipping point. You are about to face irreversible contamination."
"Spent Exoliser has been retired."
"We are down an Exoliser. Working on backups."
Completing a round
"The Void Cascade just hit a new level of intensity. Be careful. We have no idea what it could manifest."
"Void Contamination critical. Do these invaders have any idea what demons they have invoked upon us all?"
"Readings are off the charts. I don't know what sort of nightmares you might encounter."
"Contamination just spiked. Keep your wits about you."
Receiving round reward
(first round) "Hm. Our enemy has abandoned valuable supplies. This is yours now."
"Our enemy's folly is your gain."
"This discovery might interest you."
"Ah. The Void has manifested other than a nightmare."
"Enemy bounty secured."
"See what you make of this."
"Struggle has its benefits."
When initial mission objective is complete
"You're cleared to self-extract when you're ready."
"I've opened an extraction route. Your choice when to use it."
"Extract yourself when you need to."
(when Cascade meter is nearing maximum) "The Void Cascade has surpassed the tipping point. It's lethal now. Leave the area while you still can."
"Destabilising the Zariman is a foolhardy strategy. The Void has already started to degrade our enemies' judgement. You did well to stop them."
"Good work. You did all you could out there."
"You did everything you could. I've secured enough cleansed Exolisers to keep the Cascade at bay for now."
"Hey. Talk to me! Oh no…."
"Kid? Tenno? Say something. Can you hear me? KID!"
"Hey… kid… you can't give up on me now. KID?!"