Editing Warhammer 40,000/8th Edition Tactics/Adeptus Custodes (section)

====Chaos====
*'''Chaos Space Marines:''' May the Chaos gods have mercy on your opponent if they are using the Black Legion Tactics, otherwise you're going to stomp him harder than you already will with attacks that explode on a 4+. Alpha Legion and Iron Warriors play out like Raven Guard and Imperial Fists, respectively. Read the loyalist marine section to see how you deal with those. The closest analog Slaanesh type shooter units can focus fire and wipe out your units if they get in range. Berzerkers don't give a fuck how tough you are (but they are soft themselves, charge first) Tzeentch and Nurgle guys are tougher and throw psychic bullshit at you. They can combo up some pretty nasty warlords as well. Abbadon is a mighty beast, but as mentioned, the Custodes can fuck him up proper. 
*'''Chaos Daemons:''' Hordes of daemonic freaks galore. Nurgle Daemons have Disgustingly Resilient which gives them a 5+ shrug against all of your attacks. Your guys will have to put in double time to get rid of them. Khorne Daemons hit like freight trains on the charge with a potential 2 damage coming from a basic Bloodletter's sword. Tzeentch Daemons will spell doom for you with psychic spam, akin to the Thousand Sons below and the Grey Knights. Ironically Slaanesh's daemonettes will be a cinch at range considering that they can only get up to S4 on their units and are way too fragile against ranged attacks. Assault Cannon Venerable Contemptor Dreads and the standard Jetbikes will rip holes in their number quite good, and avoid close combat with their greater Daemons unless you throw a squad of Stormshield guard at them since Greater Daemons struggle to get around high invuln saves in close combat.
*'''Death Guard:''' Mortal wound spam (both psychic and non-psychic), plus Mortarion. Have fun! They are not very numerous though, but they are disgustingly resilient. Pox walkers, on the other hand, form their screens and are quite the tarpit. Their elite infantry is also very tough potentially resulting in prolonged combats, something to keep in mind.
*'''Thousand Sons:''' Mmmm… did somebody say ooey-gooey Psychic cheese? With Custodes alone, you do have the Spark of Divinity Stratagem to Deny the Witch, a built-in 6+ against wounds caused in be Psychic phase, and the Impregnable Mind Warlord trait to Deny and get a +1 when doing so, but you're going to need more. They can spam their powers while you cannot spam that Stratagem or a Warlord Trait, so ally in either other Psykers or take Sisters of Silence. Think of the Thousand Sons Psychic phase as a second Shooting phase, since nearly everything can at least cast smite. Additionally, all their basic guns are AP -2, the perfect AP for taking on Custodes as you’ll pretty much always be using your 4++ to save. If your opponent is taking Magnus, remove him quickly, using a Telemon's Fisters or an Ares’ dakka; he’ll buff himself up and others if you don’t. It also doesn’t help that Rubric Marines and Scarab Occult Terminators have All is Dust to give them -1 to hit, and they’re pretty tanky too. Removing whole units at a time is key here, as it removes one more Psyker each time.
*'''Renegade Knights:''' Like Imperial Knights, but even nastier in close combat. Even after their Codex, they still play very similarly to their Loyalist counterparts.
*'''Renegades and Heretics''': Think Guard, but with all their strengths and weaknesses amplified. Their fodder is even more pathetic, but they can field so much of it, it is a possibility you will literally not have enough guns to kill all of them, unless you brought Allarus Terminators or sniper allies, and kill all of them you must, as their Enforcers almost completely negate Morale loses. Meanwhile, their vehicles may not be quite as mean as their loyalist counterparts without things like Regimental Doctrines or Tank Orders, but a Leman Russ Demolisher is still point-for-point the nastiest tank in the game, and the boys in R&H can field a LOT of them.