What if factions had their own way of creating portals to their respective dimensions? They made it here, so they clearly have the technology for dimensional shenanigans. As an emergency or expansionist measure, they could open a short-lived call to arm or spend months growing/building a structurally sound gateway (depending on faction and situation). Your map would show the portal event to either warn you to stay away, or to let you run in there with a shotgun to shut down the operation before it even begins. Of course, along with the ability for enemies to open portals should be the ability for the player to close portals. This could be a special gun or grenade that “blends” dimensional fabric in that tile momentarily, disrupting the delicately balanced conditions needed to maintain the portal and violently flinging anyone on the tile away. Ideally it would be high-skill, expensive, replenishable, and need some tool from a lab or Exodii mission.
The Triffids:
The Triffids are structured. They have a leader, a goal, and various carefully engineered servants. Kevin seemed to be in support of culturally expanding Triffids with new plant-based buildings and quests, so they definitely have a social structure.
- Trifid Gate: After sufficiently scouting out the local area or encountering a concerning enemy force (Mycus, large hostile human camp, after surviving an attack on “Triffid HQ”, etc.), the Triffids have decided to call in the next wave of plant-based colonizers. You see (from the overmap) a quartet of tree trunks reaching towards the sky and spiraling together in to a single point. Over the span of two months, a Triffid Gate will be constructed in the area between the four trunks. Small transport drones will be sent out across the surrounding area to gather organic material for the project (perhaps with squads similar to Bioshock’s Big Daddy & Little Sister system). This could be limited to only have a chance to happen in spring to make Triffid groves easier to monitor. If a Triffid mission system is developed, there could be transport drone escort missions or rewards for delivering organic material.
XE037 & Undead:
XE037 is an intelligent extradimensional force with a mastery of dimensional rifts and Lieutenants & other intelligent minions at it’s disposal. Perhaps some of XE037’s more powerful minions have limited dimensional powers themselves.
- Storm Heralds: From within the largest Wandering Hordes comes Storm Heralds. They resemble both shocker zombies and necro-boomers, but energy courses within them rather than around. They play the important role of securing victory against larger interdimensional threats. If destroyed, they cause a large explosion which tears nearby creatures to mincemeat and creates a short lived shimmering portal that summons various Netherworld inhabitants, severely crippling the horde. If an enemy gets too close or they see enough of the horde die (based on the sum of their individual difficulty number), they take 800 move-points before releasing a shockwave that knocks creatures five tiles away and creates a Decaying Rift, a week-long portal that lets the evolved armies of The Blob’s previous conquests join the invasion.
- Zombie Scientists: They have “a glimmer of awareness - not a human awareness, but something more sinister”, which I interpret as meaning that they are being passively guided by the intentions of The Blob. When first alarmed, they would scan the nearby area and run to a terminal if one is found. If they reach the terminal, “you hear rapid clicking” and have 300 move-points before “you here blaring alarms” and portals start appearing on nearby walls. The portals would be from highly-experimental human tech with only a touch of XE037’s influence, so they are all short lived (4 hours?) and probably not all leading to one of The Blob’s dimensions. If you’re lucky, the various factions popping out of the unstable portals will kill each other off. If the zombie scientist does not detect a terminal when you alarm them, they’d just rush at you with murderous intent as usual.
The Mycus:
I don’t see the Mycus using portals. They are a nearly unthinking biological wave that spreads outwards for the sole purpose of being all encompassing. However, with their replicative abilities reduced they’ll need a way to expand their ranks. The Mycus must grow.
- Throbbing Lumps: A growth near the boundaries of Mycus territory to expand their claim on everything. If there is a X(96?) long line of Mycus tiles in a direction and no other Throbbing Lumps in a radius of X, spawn a Breather-like creature that summons spore clouds and fungaloid sporelings. If the Throbbing Lump is destroyed, a wave ripples outwards and all fungal tiles within X/2 tiles are destroyed. Fungal creatures on the tiles as they are hit by the wave lose 1/3rd of their health. Throbbing Lumps are marked on the map if you see them. Note: Overmap tiles are 24x24 player-tiles each. As a side note, myci can be decommissioned and harvested for valuable fluid sacs and fibrous stalks, which are repurposed for vegetables and plant fibre. I propose letting the player grow Lumps by planting Marloss/fungal seeds, which are only found in fungal towers. Being able to grow a Lump in a premade trap hall to farm supplies would give players a reason to directly attack the Mycus other than to join them or tediously purging their presence, rather than just avoiding the area.
The Exodii:
Portals are their thing. They exist because of portals. Others adopted portals. The Exodii were born through it, molded by it. Even so, their portals are intended as an escape route for when creatures evolve or amass beyond what we’re seen yet. If you befriend them and engage in trade, maybe they’ll sell you some old models or blueprints.
- Intradimensional Bridge: A structure that permits instantaneous teleportation to another Bridge in this dimension. The Exodii will prioritize their construction immediately after securing the area where they dropped/landed. This will allow travel between Exodii camps that have them set up. They’re still working on interdimensional travel, but even our scientists figured out basic intradimentional travel in the relatively short time they had.
- Interdimensional Bridge: The same model of Bridge that they used to get here. Building these is a low priority and they are left inactive, but they are built anyways in case a quick escape is needed. The controls are foreign and hopelessly complicated, but every member of the camp is taught how to operate them so survivors can escape a freak accident no matter who is killed. Using these Bridges consumes rare materials, causes them to break down shortly after use, draws the attention of dimensionally sensitive creatures, and strengthen the fabric of reality in the area / makes local teleportation more difficult. To befriend the Exodii, earn their trust, be taught their technology, and be accepted as one of their own only to paint a target on their back and leave them in a portal dead-zone after using their only means of escape would be a betrayal of the highest order.
Humans, Insects, Mutants, etc. :
No portals. Despite being significant factions, there’s no reason they should have portals. Humans hadn’t really figured them out, insects are dumb animals, and the more feral mutants are just a step above animals. However, the occasional rare dimensionally-oriented weapon drop seems reasonable enough.
- Anti-Portal Gun: Although the concept was already in development, the models hastily produced and distributed during Year 0 by the few living scientists to the fewer remaining generals to the practically extinct armed forces were little more than polished prototypes. Despite their expensive repair costs and tendency to decay on use, they achieved their goal of reliably blending dimensional fabric from a safe distance. “Blending” in a similar way that a kitchen blender breaks up large chunks to create a smooth mixture, the APG stirs the targeted fabric to disrupt the conditions needed to maintain the portal and leaves behind the usual stable reality. Could be acquired through military loot, labs, or trading with Exodii.
- Disruptor Grenade: Spawned from a general’s desire for a stronger blast, a malfunctioning APG prototype, or maybe both, the Disruptor Grenade is a larger radius and faster-to-use dimensional disruptor with a lower energy cost but also far less efficient material consumption. With a radius of 6, no direct damage, and a ridiculous knockback that could send creatures flying across overmap tiles, Disruptor Grenades are ideal for collapsing portals without a clean line of fire, freeing yourself from being cornered, or making more…daring… escapes by blast jumping with the shockwave itself.
- Rift Spear: Less of a ‘spear’ and more ‘experimental danger on a long stick’ designed to keep the user as far away as possible, the Rift Spear is the creation of a dimensional scientist’s desperate efforts to fend off the dangers associated with their line of work. Fragile weapon. Reach2. Recommended to be used on empty tiles not adjacent to user. On use, create a cloud of tiny dimensional rifts around the zappy end with a chance for it to spread to adjacent tiles (like a small SHOCKSTORM). The cloud lasts for about 300 move-points. Walking in to the rifts causes very high damage and knocks the target backwards. Intelligent creatures are frightened by and stay away from rifts. A rift cloud forming over terrain or a creature deals absurd damage. Rift clouds destroy weak terrain and damage moderate strength terrain (wood).