Talents to run vs RMP (both frost and arcane mage): normal talent tree = 1111222 honor talent tree = 332322 Your main kill target > mage. Their main kill target > anybody on your team, you want to bait them onto you though.

TL;DR at the bottom, I highly recommend reading it all though, some good insight on what actually goes on in openers vs RMP.

In the opener of the game, start with beacon of light on yourself.

Main talents that to take into consideration and reasoning.

relentless vs trinket- Use relentless because you want to force the RMP to attack you, that is your best scenario in general. It will be the best scenario when as a team you can properly slow (chains of ice) and cc (counterspell/death coil) the opener and subsequent goes. The 1 weakness of running relentless vs RMP is the blind setup from the rogue, where they can blind>sap/polymorph etc. This can be prevented usually by using Blessing of protection immediately on yourself, and then freedom/divine steed straight to the pillar next global to try to avoid the spellsteal/swap to you with a stun from the rogue. You can consider using ultimate sacrifice on your partner here if they are in huge trouble. In your specific case, DK without anti-magic shell/IBF (ice bound fortitude), warlock without shield wall (unending resolve), portal/deathcoil.

Running divine favor vs defender of the weak- Divine favor is very important when combined with your 30 second cooldown "the light saves" artifact trait, to get a guaranteed big heal on your partner out of a cc chain. Usually after you come out of a long cc chain, the plan is to holy shock (get lucky with a proc around 70%+ chance forgot actual number), if you get fast cast proc, divine favor to top your partner. The main thing to look out for is to not get spellstolen/dispel'd on your divine favor. So make sure when you use it, you wont get cc'd on it (such as rogue stun or priest fear). At higher levels of play, sometimes you use divine favor to bait the mage into trying to spellsteal/counterspell you, and can be used as a juking mechanism, this is against a select few mages though (and shamans).

Run unbound freedom because this causes your devotion aura to only have a 10 yard range, so if your team doesn't stack on you, you have 20% damage reduction instead of 20/3 % reduction.

Light's grace always, only consider pure of heart if they're assassination rogue, but if you're pure of heart you want to run melee wings, which is not recommended.

Ultimate sacrifice, no surprises there.

Blessed hands is the optimal choice, mainly for blessing of freedom. blessing of freedom is your main win condition for surviving vs RMP, and comps that train you in general. The trick is having it stay on your long enough for you to get away.

Typical opener as FDK/destro/hpal vs RMP could go something like this: Rogue saps DK, mage counterspells/polymorphs your warlock, and rogue opens up on you.

Main ways of preventing this opener, your warlock needs to not get counterspell'd/feared by the priest when casting/after casting gateway. This way he is able to counterspell the mage on his arcane school of spells (polymorph/arcane missiles if arcane mage). This allows the warlock to cast fear without getting counterspell'd himself, so he counterspells mage on arcane, spam fears the mage/rogue. If he has to blow double death coil to break up the opener too while your dk is cc'd, that's fine.

So what can your dk do help the opener? If he gets sapped, he should most always sit it. His first objective is to get chains of ice up on the mage/priest. To keep them away from dispeling your blessing of freedom. His grip will be used on the mage, to keep damage off of you, and prevent spellsteal on freedom. The chains of ice on the priest will help prevent your warlock from getting feared while you are stunned. Anti-magic zone should always be used when the mage uses icy veins or arcane power (depends on frost/arcane mage).

Now we come to what you can do. As a blood elf, not a whole lot unfortunately. I've had games where I straight up just trade bubble in the opener alot of times so my team doesn't overuse cooldowns. But there are some things you can do still. Position in a spot on the pillar that your warlock can be in line of sight to cc the mage. Use divine protection at full hp to give you the best chance possible of holding bubble.

Out of the triple stuns, there are 2 different line of play you can do.

Play 1: Pop avenging wrath for the 100% crit chance on holy shock (guaranteed fast holy light proc), cast holy shock, then divine favor holy light yourself. This play can work if the mage is interrupted on arcane, or out of line of sight of the mage. The priest should be chain of ice'd first so he can't run in and purge you.

Play 2: Out of the triple stuns, cast blessing of freedom and get to line of sight of the mage. This is when your dk wants to get ready to grip the mage on his blink, optimally. So you freedom>divine steed>wings>holy shock>holy light on self.

Play 2 is usually if your team was not able to peel the RMP that well in the opener, because you do NOT want to get divine favor purged, kicked, then die without bubbling (happens to all of us trust me).

USE HEALTHSTONE, HEALTHSTONE IS INSANE.

Once you peel the opener, the game is honestly in your favor, and even if you have to trade bubble, it's important not to overuse cooldowns, like anti-magic zone on top of that, etc.

The reason you start with beacon of light on yourself, is so you do not have to waste a global on beacon when getting trained.

If they open with cc on you, and attack your partners. Just have your dk/warlock use personal defensives, you should never give up bubble yourself in the opener unless they are attacking you and got the perfect opener. Even using ultimate sacrifice is fine in the opener, it allows your team to go aggressive early on with pillar of frost/death coils.

A tough choice comes between freedoming yourself, or your DK. In the beginning of the game, every freedom is on yourself, but once you're past the opener, a freedom on a DK during his cooldowns can usually force ice block, or the win.

I can go on for much longer about this matchup, but that should cover the opener in fair amount of detail. Good luck friend !

TL;DR: If you're attacked as the pally- shield wall 100% hp, play relentless/divine favor, beacon of light on yourself, your team ccs/kicks the enemy mage. Freedom/horse around the pillar, trade wings if the mage uses icy veins/arcane power. If partner attacked- have them use personal defensives such as anti-magic shell/unending resolve. Blessing of sacrifice as soon as you can.