The perfect "End Game" mission: It's MD, you need the data mass to pull codex entries from the ship/planet systems; It turns into an Exterminate, 5x credits; It's now a Cap and there's 3 capture targets you have to cap and if any leave you fail this segment getting no rewards; Oh, someone died it's not a survival while the Operative revives the dead player: Survive 10min and keep the LS above 0% to revive down tenno at LS capsule. If 0% is reached player stays dead and mission type could be any available mission type and dead player gains only what was earned up to point of being dead. Players can re-initiate survival mode in addition to any other mission types by interacting with the LS capsule on random map tile after failed attempt. Survival mode initiates only when (a) player(s) died with 1 chance to revive after every 3 successful mission completions; It's now an Excavation mission. You need power cells to power the excavator and it will have a hacking console on it that can trigger one of several things depending on successful or failed hack. On sucessful hack on excavator, 20% power is consumed and either the excavator will be "repaired" or gain a temporary shield (similar to Frosts Snow Globe). On failed the excavator will lose 20% power and do a "reboot" over 10 seconds OR the console will blow up doing damage to the excavator; It's now a Rescue mission, (insert formula for Rescue mission on PoE unless tile is implimented). Yes, spy and sobatage can be a mission type but those are "special".
This is meant to be lv60+ enemies and being a single mission session where, similar to arbitration, if a player dies they're out cannot use revives, however, the bleedout timer should still be a thing. On that note i feel it should be possible for a player to "re-power" thier warframe being able to load in with their operator every 4 minutes. And the player has to get to where the warframe "fell" so it would be important for the system to retain the model of the now down warframe (unless it's Nidus). There should be a special ruling for those who use Nidus though not to make people "use" Nidus exclusively he is the "infestation" warframe. Nidus should have a special rule where while "dead" the frame can send out a maggot every 10 seconds which can return to the warframe to "give it power" and has a power meter that once it's 100% the player is loaded back in controlling Nidus WITH A CHANCE TO FAIL and instead the player might be watching their warframe attack the other players which has to be defeated before the player owning the Nidus warframe can "claim" back into it.
The idea of this special mission is not to have a set "map run in and complete then leave" but more on the endless mode where once you complete the initial mission you "can" extract with option to do more mission segments and similar to the normal survival modes the longer you stay the higher the enemies scale up.
Sabotage and Spy should always be "an optional" mission any of the players can do. Sabotage can put the ship/base in a state of wreckage where should everyone extracts within the 5-10min before meltdown everyone can get a special reward. Failing to leave should put the ship/base in it's wrecked state with assumed 0% LS (any frames with a cheat death mechanic that require another thing to exist such as Khora or Loki do die) and those frames that did die can load in as operator mode (in 0% LS state) and collect their frames which is requried to extract. Notes that the only enemies that should spawn during 0% LS mode should be non-organic machines but i'm sure the Infested were biologically engineered to survive without air so whatever.
While players can extract separately there is a bonus reward (which should be 100k credits, an ayatan, Endo, Special mod) if everyone of the team extracted depending on how many missions they completed, the more missions completed (excluding revival survival) the better the reward. Any Players who "did not extract" and get "left behind" get to enjoy removing a variation of a G3 bolt which (while on) can cause your warframes abilities to be locked randomly, your warframe might drop it's weapon(s), the warframes energy might drop to 0 for no reason and a low chance your frame will go into bleedout. HOWEVER, if SOMEHOW you get grouped with one of the people of your group (which would only be 3 other players max) you can interact with their warframe, go into a cinimatic of the "G3 bolt variation" being removed and placed onto the other frame which increased chances of each hindering effect happening and the player who had just removed it starting from that moment with 0 energy and 0 sheild only for each to restore and retain as normal and the other player cannot do the same and in fact the "G3 bolt variation" requires more materials to have removed (from that frame) with the exceptoin of Nidus. I don't know what's up with Nidus but after a week it just disappears and that frame let me tell you it gets hungry i had some chips and cereal the next day all i found was trash and Nidus and wouldn't you know it the milks empty too where did my leftover burger go?
SPY is meant to be a "reset button". Say the ship is in 0% LS state and wrecked for example, this would allow the players to restore the LS state and/or cause "WORKER" units across the ship/base doing their repairs (similar to those nuetral enemies on Ceres). This is not to say that Spy should only be used as a "reset button" but can be effectively spammed for the "spy rewards" where each time there are more enemies and EVEN enemies that can be on any of the consules to interact with the console for such things as "going into the room" or activating a door to open, a bridge to form to then walk across, but not to remove the security beams as they can just walk through those without triggering the alarms.
Let's talk about Exterminate, this is not the same Exterminate everyone on the ship/base you know and love. Throughout the map are going to be Eximus enemies, killing any of which will bring up the kill count to how many Lotus/Ordis would need you to kill which typically should be 20 and max at 50. No one wants to have to kill 50 eximus's when there's only 2 every 5min but by the time players have spent about 20min doing the mission types there should be plenty to warrant 50 enemy kill count requirements.
The idea as you read in the first paragraph thing above at top is that completing each mission type rewards you different things but not in a "AABC" rotation.
Ext should be rewarding on itself where the more enemies you kill the more credits you get with 5x credits. So i can understand if the kill count is 10.
Cap is meant to reward a special Blueprint like any weapon or frame BP but not Prime.
MD is meant to reward Codex Entries relevant to the enemy type of the planet. And/or relics.
Rescue is meant to reward the standard spectre Bp and relics.
Excavation is meant to reward Relics/resources (such as 2 nitain or 5 Neural Sensors).
Spy should be the standard spy rewards, why change something that's good.
Initiating the Sabotage and extracting successfully should reward the players with lots of credits, a bunch of relics, Alot of Endo, Kuva, those sorts of things.
Defection can literally be implimented as part of the rescue where first you have to save the people and then you have to escort them to the capture fail room with the ship to complete the rescue.
Why have Defense at all when you have Mobile Defense, which BY THE WAY if any one paying attention if you lose you cannot continue doing several of the things such as initiating the Sabotage which means someone in the team is always handicapped to not being able to use their primary weapon so to hold onto the datamass.
The REAL challenge DE is going to have with this is when an enemy would had been "alarmed" and left alive by the players and gets moved into a room with enemies that are not alarmed but because an alarmed enemy is in the room the enemies of the room are then alarmed. I feel there should be a "madness" mechanic for the enemies where they would kill the "mad" enemy like it was an animal that needed to be "put down" for being defective and a risk to the war effort.
Thank you for your time to read all this, i've played over 5k hours of Warframe but what do i know....