Maybe each boss could be fought individually before retreating further into the Kings Lair where you have to deal with all three at the end. The bosses I'd have in mind would of course be the Kings head Archon Preist, Their Prime Servitor and the Kell of Kings. The Archon Preist would be like a master of all the machines and devices in the lair. He will summon high servitors to shield him, massive waves of all kinds of shanks to attack you and eventually Archon servants to guard and repair the servitors while he sets off traps on the battlefield that you'll have to avoid or disable. I'd imagine the battle starting off simple with just the Archon and a massive group of shanks waiting for you. After you clear all the shanks he will start setting off the devices/hazards on the field, and he will repeat this until you can manage to find a device on the field that will stall the arrival of reinforcements so you can get clean uninterrupted damage on him. Once he receives enough damage the high servitors (probably immediate subs to the Prime) will arrive and shield him, the same process as before will repeat only once you clear the enemies and disable the hazards and access for oncoming enemies you will have to destroy/damage the servitors- one of which maybe could be carrying a relic-type weapon that will help you more quickly disable the devices for the rest of the encounter. Once the servitors are taken car of you may have a small window to deal Archon damage but most likely will have another horde of shanks arrive, alongside archon servants who will try to service the servitors back to operating condition. Unless you can run through the enemies and disable the are hazards fast enough you will probably have to deal with all the servitors again, however one of the archon servants will drop another relic that will help you more quickly damage the servitors. Once you have both relics you should be able to repeat the process in enough time to have a decent window of tie to attack the Preist, if any of your relic holders die the relic will break and you'll have to obtain a new one from one of the previously mentioned enemies. If your team takes too long (lets say seven or nine summoning of shanks) than the Priest will 'enrage' and start summoning a unbeatable number of higher tier fallen reinforcements. The Prime Servitor of Kings would be the next boss after the Priest flees and sets off a presumable maze of puzzles and traps for you to navigate. The Prime's main gimmicks will be that he can shield himself from harm unless hit suddenly with massive amounts of damage, and that he is very mobile and can teleport to key areas of importance or safety where he can go all cqc and quickly blast you. The Prime will be guarded by fewer enemies than the priest encounter but the enemies will consist of a no shanks and more fallen. There will be numerous amounts of Dregs as fodder and vandal snipers all about, however the main focus will be the captain archon servants who will be following the Prime closely with unique weapons. Your team will have to attack the prime enough to gain their hate and lure the captains away so you can kill them and acquire their weapons that are exceptionally powerful for bursting down AND stunning the Prime (probably some Arc/EMP-like equivalent to the previous fallen launchers we've seen) I'd say about five of the dozen captains will be carrying these and you'll need about four to fire a charged/concentrated attack at the prime to de-sheild and stun him. The weapons can be used on other enemies but if charged can only be used once before going empty. Once the Prime's health is lowered enough other servitors will arrive to shield that Captains, however the servitors can be quickly killed if one of the players doesn't use their EMP-cannon on the Prime and instead saves it. Toward the end of the encounter any dregs left on the field will rush to the prime and sacrifice themselves to regen it's health immediately after the damage phase. During this entire encounter the Prime will be charging a special attack that will act as it's enrage, deaths will feed this charge and give your team less time before enrage. The third individual encounter will be the Kell of Kings. The most aggressive and tanky of the bosses, you will need to crack his ultra strong armor. However he will constantly be focusing on running down and killing at least one of your fire-team members, presumably whomever shoots him enough in a vulnerable spot (Ether tank perhaps?). This boss will have most likely the most adds guarding him and arriving to help throughout the encounter, though probably start off with weaker deployments like dregs and shanks, eventually working up to servitors and captains. However, the trick to fighting the kell will not be to attacking or stunning him- but instead to be coordinating both his hate and that of his most powerful guards in one spot. On he outer edges of the arena will be Fallen walkers that will be as you can imagine be focusing on decimating you. The walkers and the Kell will not focus the same target, so your team need to get them so their line of fire will land their shots on the Kell- dealing massive damage. This encounter will probably be the most hectic one but also the shortest of executed quickly, which will be the goal since dragging out and making the damage come slowly will eventually case the tougher adds to spawn (though they will also be vulnerable to the walkers cannons). Once the Kell is brought down to a quarter health his armor will crack an you can lay into him normally until his health meter depletes and he flees as well. If the encounter dose drag on too long and the adds don't manage to wipe your team, the Kell will summon his throne that will act as a transport as he call for elite reinforcements that will come in the form or the lesser archons whom will be shielded by high servitors and a fat horde of stealth captains. The final encounter will be against the triad of the House of Kings bosses. Each will protect one another and will behave in a specific manner. The details of how to complete this encounter I will not spell out, but I will tell you what happens depending on how you go about it. The Prime will be acting as the enemy bosses healer, it will stay back in a generally fixed area and shield one boss while granting healing ether to another, the Prime continues this until it's shield it is providing is broken which will overload the Prime and stun it. Once recovered from being stunned the Prime will only sheild one of it's ally bosses and be unable to heal the other for a specific duration of time- this time is consistent with how long the Prime was left stunned. If your team get's too close to the Prime early in the encounter, both of the other bosses will rush and attack you. The Archon Priest will shadow the Prime as a body guard and will shoot at your fire team from a distance, targeting whoever focuses the Prime the most and stopping the attack only to quickly repair the Prime once it is stunned. The Priests repairs will mostly shorten the duration of the Prime being downed, but will also slowly heal the prime until it recovers to it's normal state. The Prime's time left stunned can be maintained longest if the Priest is continually attacked during this time, however the priest will more accurately and aggressively fire upon your team while being attack during the Prime's time spent stunned. During the entire encounter your team will be relentlessly chased down by the Kell whom the Prime by default will be shielding unless your fireteam deals too much damage to the priest in a short amount of time or breaks the shield that the prime is granting. The Kell's focus and aggression can be obtained by aggressively attacking him, however if either of the previously mentioned things are done the Kell will refocus to your teams heaviest damage dealer. When the Kell is granted healing ether his movement speed will increase. The final encounter's enrage will be reset if one of the bosses is killed, if not the initial enrage will come in the form of the Kell and Archon Priest summoning their thrones that will raise them to safety while the Prime shields them both, at which time the Archon will activate all the hazards on the field as the Kell summons stealth snipers to fire upon your team. The pattern of behavior changes upon killing one of the bosses as well. I will elaborate on that down below.