The next 2v8 mode
With 2v8 destined to make a comeback with some improvements at some point in the future, I just thought I'd theorycraft a little and give what my suggestions for it could be expanded with, although I'm sure BHVR have ideas for it already, I hope these ideas would be considered.
Killers
An expanded killer roster is a must. I'm not sure if licensed killers will be included, but I'm going to assume not for the sake of this. I'm not expecting an exhaustive killer roster for the next 2v8 mode, so I'm thinking the following 5 original killers would make good additions, and double the roster.
Hag
Lisa has to introduce Hex Totems to 2v8, there's no way around it. In turn, I think survivors should get a new class that makes use of totems, but more of that later. I don't think Ruin as is would make a good addition to 2v8, but with the expectation that there won't be a vast amount of Hex perks added to 2v8 anyway, I think a more generic and simple route would be best.
Team Skill: When a survivor triggers a trap, they scream and their aura is revealed to both killers for 5 seconds. When a survivor wipes a trap away, their aura is revealed to both killers for 3 seconds.
Innate Skill: 5 Hex totems are ignited at the start of the match, each totem reduces action speeds (repairs, heals, chests and exit gates) of survivors by 3%, up to a maximum of 15%. Survivors are inflicted with Oblivious while interacting with a totem. Increases speed of setting traps by 30% and range of teleport by 12.5%.
Hag would make a decent support killer similar to Trapper, but with her traps being a little less lethal, particularly if out of range to teleport to, she gets slowdown in the form of Hexes to make up for it.
Doctor
Herman's main gimmick is having a virtual map presence, while he's more or less a basic killer with no mobility, he can 'appear' to be everywhere, whether by illusion or via Static Blast or even survivor-survivor static transference. So the best way to synergise would be to extend this to the other killer to build on this virtual presence, particularly given how large the 2v8 maps are.
Team Skill: Survivors within the terror radius of either killer are struck by Static Blast. Illusionary Doctors can also take on the visage of the other killer.
Innate Skill: Tier II Madness spawns Illusionary Killers and Tier III Madness triggers a permanent red stain.
Doctor effectively gets double the effective area of Static Blast coverage with two distinct 32m radii (3200m square each), which is equivalent to a 46m terror radius (6600m square) or both Calm add ons, which I don't think is unreasonable for a significantly larger map. There's also the chance that these terror radii overlap and reduce your effective coverage as well. But in light of how versatile this could be, and the chaos it would inflict on survivors, especially with some stronger killer partners, I'd forego any adjustments to Static Shock. The illusionary killers are a novelty more than anything.
Spirit
Similar to Wraith, Rin is a rapid moving ambush killer, but unlike Wraith it doesn't make sense for her to grant her companion a stealth ability, both to differentiate her from Wraith and avoid redundancy in a Spirit/Wraith pairing. I think her lethality should shine when cooperating with the other killer, as she's already going to be strong in a solo situation.
Team Skill: Phasing within 4m of the other killer grants them a +60% speed boost for 3 seconds or while still within 4m of the Spirit. Both killers can still see the aura of the other killer while Spirit is Phasing.
Innate Skill: Increases duration of Phase by 3.5 seconds and speed of Phase by 15%.
Didn't want to give Spirit too much in the way of buffs as she would be a pretty strong killer anyway, but the duration/speed increases would help her to traverse the larger maps a little easier.
Clown
Admittedly I'm not well versed in Clown, I don't own him, I don't really like playing against him, but I think he could work quite well in 2v8 and his power is perfectly suited to assisting the other killer.
Shared Skill: Both killers can make use of the speed increse from yellow bottles. If both killers pass through the same yellow bottle mist at the same time, their speed increase lasts for 3 extra seconds. Direct bottle hits reveal that survivors aura for 5 seconds.
Innate Skill: (I'll leave his basekit/add-on adjustments for someone more experienced, probably include additional bottles or something like Huntress gets more hatchets)
Legion
Legion is a tricky one. Being able to rapidly injure survivors is mitigated by the inability to down them while in frenzy, but that isn't as restrictive when there's another killer about, however without the same speed as Legion the other killer can't really capitalise on that too easily. So I figure info could be the perfect shared skill here, in exchange for a slightly less lethal power (similar to Billy) so that essentially Legion is nerfed in order to provide assistance to the other killer.
Team Skill: Survivors hit by Feral Frenzy are revealed by killer instinct to the other killer for 4 seconds. (basically the inverse of Legion, while Legion sees survivors who haven't been hit, the other killer sees the survivors who have been hit, for a short period, allowing the other killer to combo off Legion if positioned correctly)
Innate Skill: Survivors are now only revealed by killer instinct for 4 seconds upon activating Feral Frenzy, hitting a survivor with Feral Frenzy, or when entering your terror radius during Feral Frenzy. A fifth hit is no longer an instant down, instead Legion can continue to hit non-deepwound survivors up to 5 times in succession. The 5th hit will still inflict deepwound but will also immediately end Feral Frenzy and hinder Legion for a couple seconds.
Survivors
Change to unlockable skill: In addition to activating on death hook, I would add in a further caveat. It would also activate when three survivors remain in the trial, regardless of hookstates. This would partially hinder killers from slugging the final three to prevent the hatch from opening.
In light of how effective and oppressive a double-team can be for killers, I think something should be added to make it a little more viable for survivors to play around these situations. Considering that killers in this situation have the ability to doubletap survivors and burn through health states in an instant, without any avenue of escape for the survivor. I think the best thing to add would be an Endurance effect that kicks in only when chased by both killers at once. This would provide one additional health state, so a 50% increase in health states, to counteract the fact that killers are effectively 100% more lethal.
When chase is triggered with a 2nd killer, you gain the Endurance effect for 10 seconds.
This is still limited to 10 seconds, so you can't indefinitely occupy both killers time, but it does give you that window of time to make a play that isn't guaranteed death. Some people are going to think this is too much, to which I say to keep in mind this is still only available when on death hook, or when only three survivors remain, it's more of an anti-tunnel mechanic than anything.Some people are going to think this isn't enough, to which I say that 10 seconds might not seem like a long time, but it is precisely the time the second killer is likely to make their attack, and at the very least, it will give you a chance to make it to another vault or pallet.
New class: Seer
Maximum: 2 per trial
Aura Skill: Able to see the aura of totems within 16 meters.
Innate Skill: Activates on cleansing or blessing a totem. While injured and entering a locker, remaining in that locker for 7 seconds will recover a health state, upon exiting the locker after 7 seconds, you see the auras of any survivors or killers within 24 meters for 4 seconds, and the skill deactivates.
Team Skill: Can bless one totem to grant the following effects; within a 24 meter radius, survivors auras and scratch marks are hidden, and persists for 3 seconds after leaving the area. When a killer snuffs this totem, their aura is revealed to all survivors for 5 seconds.
New class: Looter
Maximum: 2 per trial
Aura Skill: Able to see the aura of unopened chests and undepleted items within 16 meters.
Innate Skill: Begin the trial with 3 tokens. Unlocks the ability to rummage through a chest for an additional item, consuming a token. As long as you have at least 1 token, your aura is hidden while performing unlocking actions and the sound of your unlocking action is reduced by 75%.
Team Skill: Improves the item efficiency of yourself and other survivors within 8 meters by 33%.
These two new classes are each limited to only 2 per trial, rather than 4 as with the other classes, simply because their effects can be problematic if stacked too much. More than 2 Boon totems would be overpowered, meanwhile multiple survivors fighting over chests to open would get very tiresome, and littering the trial with multiple rummaged items, particularly toolboxes, could be too effective for genrushing.
It's my hope that by encouraging engagement with side objectives, totems and chests, it helps improve the variety of survivor actions and overall slows the game down a little, while the protection from aura reading makes it a little easier to evade killers and slows down the killer snowball too.