Meralygos

 Abilities in Combat.

 How does the Red Dragonflight fight? Note. I've selected some fights to stay within 20,000 words. Many lesser NPCs have been discarded.

•  Axtroz - Drake champion of Grim Batol. Uses  Rend, strong physical damage,  Flame Breath.

•  Belnizstrasz -  Fireball,  Frost Nova,  Arcane Intellect

•  Narillasanz -  Renew, Flame Breath. Rare elite.

•  Vaelstrasz the Red -  Essence of the Red (The blessing of Alexstrasza is applied to all allies nearby. Restores 500 Mana per second. Restores 50 Energy per second. Generates 20 Rage per second. Generates 20 Runic Power per second. Instant, 3 mins)  Fire Nova,  Flame Breath,  Burning Adrenaline (Damage done increased by 100%. Spells cast are all instant. Reduces max health by 5% every second. Deals 4376 to 5624 damage to surrounding allies on death. Instant. Cast every 15 seconds on a mana-user. Every third cast on the current tank instead),  Cleave,  Tail Sweep.  Vaelstrasz is also seen as a capable enchanter for during the classic version of LBRS Vaelastrasz projects an illusion of himself to help the heroes through the ring he enchanted himself, the [Seal of Ascension]. His illusion in human form will use: heal the entire group for 5k, heal a single user for 91k, chromatic protection (increase resistance to a random school by 75). Alternatively, he will turn into his dragon form during the battle against Rend Blackhand. Eventually, after 3 minutes, Nefarian would banish him.

•  Caelestrasz - Veteran of the War of the Shifting Sands. Makes a brief appearance in the Temple of Ahn'qiraj but his true role is played during Cataclysm. 

In the Twilight Highlands he appears as a quest giver and helps the hero escape from Deathwing. Later on, he helps the raid party to fight Sintharia. However, he is killed by her. Caelestrasz uses the following abilities:  Fireball, Essence of the Red (upon death). Fiery Barrier (huge zone that protects from shadow damage, reduce dmg taken by 99%), Phyrric Focus, Fiery Resolve--> Fire Beam

  As of WotLK most red dragons appear in a friendly guise at the Wyrmrest Temple and in Coldarra.

•  Wyrmrest Skytalon - During the Malygos encounter and Aces High, acts as a mount. Much like rogues, his bar is an energy bar. Has the following abilities:  Flame Spike (fire attack causing 943-1057 fire damage and awarding 1 combo point at the cost of 10 energy),   Engulf in Flames (launches a blast of flame igniting target for 1500 fire damage every 3 seconds. The effect can stack and will last longer per combo point),  Revivify (HoT that lasts for 10 seconds healing 500 per second and awarding 1 combo point at the cost of 10 energy. This can stack up to 5 times),   Life Burst (Huge AoE healing finishing move which increases the casters healing done by 50% and lasts longer per combo point. Max combo points award a 15k heal to all friendly targets within 60 yards over 25 seconds. Costs 50 energy),  Flame Shield (Finishing move to protect your drake. Shield surrounds you reducing all damage taken by 80% and lasting up to 6 seconds for max combo points), Blazing Speed (increase speed by 500%)

•  Ruby Drake -  Searing Wrath (Breathes a stream of fire at an enemy dragon, dealing 6800 to 9200 Fire damage and then jumping to additional dragons within 30 yards. Each jump increases the damage by 50%. Affects up to 5 total targets. Instant.)   Evasive Aura (taking damage creates Evasive Charge),  Evasive Maneuvers (Allows your drake to dodge all incoming attacks and spells. Requires Evasive Charges to use. Each attack or spell dodged while this ability is active burns one Evasive Charge. Lasts 30 sec. or until all charges are exhausted),    Martyr (Redirect all harmful spells cast at friendly drakes to yourself for 10 sec)

•  Wyrmrest Defender - Flame breath (Inflicts 21875 to 28125 Fire damage to the current enemy dragon), Immolation (Inflicts Fire damage to the current enemy dragon every 3 sec. for 9 sec.), Renew (Heals the wyrmrest defender 10% of its ealth every 3 sec. for 15 sec.), Blazing Speed, "Destabilize Azure Dragonshrine" (Attack the eruption of power at the Azure Dragonshrine in an attempt to destabilize it)

•  Alexstrasza - Gives her breath to redeem a paladin from the Scourge's corruption. It has healing properties but it fails to cleanse the corruption. Imposing physique: during WotLK, in her dragon form she was the NPC with the highest amount of HPs after Flame Leviathan (132M!)

  Cataclysm. Flame breath against Deathwing in the quest 'Battle of Life and Death'.

   Circle of Life. In Cataclysm, to gain the upper hand against Deathwing, she created a Circle of Life. The complex ritual achieved through life magic would empower her through  Life Beams (increase damage output by 20%), which were channeled towards Alexstrasza - and she attacked via  Life Blast ("a blast of concentrated life energy toxic to the Aspect of Death", 100k). It looked like an huge ball of red energy. After Cataclysm Beta, this part of the battle was removed and Deathwing burned the Circle of Life as soon as he was summoned.

  In the Madness of Deathwing encounter, she uses:  Alexstrasza's Presence (health increased by 20%) and the fire beam  Cauterize.

   Alexstrasza's Tear, an item perhaps related to her, has healing properties and may renew the soil. It was used to renew the Obsidian Forest, named so after the black dragons attacked a forest which belonged to the red dragonflight and turned it into stone.

  In the Day of the Dragon, as the Lifebinder she's able to make Deathwing feel her own pain like she did.

  In the War of the Ancients trilogy, she summons forth a copy of Alexstrasza made of stone. 

  In the Twilight of the Aspects, her flame breath is often mentioned. Once the four Aspects are empowered togheter, all of them release a pure, white beam.

  More information comming.

The Day of the Dragon. He displays great skills as a sorceror, being one of the Six of Dalaran and also being a deemed a capable diviner. Furthermore, he is able to communicate to his allies through a crystal. To counter a defensive spell left by Deathwing (the infamous Endless Hunger), he released an extremely powerful magic which summoned an explosion of light magic akin to the Sun and melted away all tentacles. It left him drained for quite a while.

War of the Ancients trilogy. Flame breath. Sorceror spells like: fire magic (such as creating explosions of fire), create portals, channel and empower his friends or foes, teleportation magic. Knowledge of ancient tongues. Capacity to speak to other people's minds. Summon crystalline spikes capable of impaling felguards on the spot, explosions of light (which temporarily blinded his foes). Noteworthy it is his capacity to raise the dead and wield necromancy (resurrects an undead goblin) due to the fact Alexstrasza controls all of life and thus her brood. note: Incomplete.

In the Twilight of the Aspects, Krasus unleashes a powerful mass of life energy which connects all the dragon sanctums beneath the Wyrmrest Temple, then they all explode. To unleash such a powerful amount of life, he killed himself. Alexstrasza says of his actions: "he used his life energy to link the portals ... to destroy all the contaminated eggs before anyone else became infected. I couldn’t understand why there was so much verdancy that remained ... Now I know. He brought death with life… to preserve other lives.

 As of Cataclysm, red dragons are the most active flight against Deathwing. Most of them can be found on the Twilight Highlands. We see several dragons NPCs fighting against twilight dragons. Like, for example, Lirastrasza who spams fireballs against twilight drakes, killing them, after being freed. They usually limit themselves to fireballs and self-healings.

•  Vermillion Vanguard - Fireblast,  Lifebinder's Boon (Channeled healing beam to an ally, heals self and ally, also restore mana), Finishing Move. 

•  Mostrasz -  Stealth.

Interpretation of their abilities.

This is just a stub. Will be expanded later on.

We often see them as the black dragonflight counterparts and ultimate nemesis. They are usually heroic and fight in an honorable way, targetting the threats of Azeroth. More often than not, we meet friendly or unfriendly red dragons, but rarely hostile ones. When they are hostile, we are usually fighting a corrupted red dragon (or we are the corrupted ones).

 Red dragons are indeed powerful combatants. They have a lot of energy and strenght and we have seen them assuming the roles of a tank (The Occulus, Ruby Drake) or an healer (Korastrasza) or a mage spellcaster (Belnistrasz, Krasus) or even that of an infiltrator, like a rogue (Mostrasz). Physical wise, they are well-built, quick and agile but also strong. Along with the blacks, they are possibly the physically stronger dragon-type [blues are likely in a third position].

 Arcane Magic. They display an huge capacity to wield and control arcane magic and are great sorcerors (see Krasus or Belnistrasz for example). In human form, we have seen most of them become skilled mages and sorcerors.

 Warrior's energy. However others can become rogues or warriors (Mostrasz). Their courageous nature and fierce strenght likely allows them to be warriors even in human form.

 Flame breath. Quite obvious. Red dragons can release flames from their mouth, reducing their enemies to cinders. A red dragon's breath appears more deadly than common flames. It should be noted that red dragon's breath is hardly (if ever) released to as fire, but rather called 'flame breath'. Flames are the visible part of fire but also hint at a more mercurial nature of the spell (whereas the word fire is associated to a more stable flame). IRL flames are described as "burning gas or vapor, as from wood or coal, that is undergoing combustion; a portion of ignited gas or vapor." Breath spells are inherent magic abilities inherited by the dragons' magic. 

The breath of red dragons is made of flames. It burns and melts the skin. Whenever a red dragon breathes upon the soil, the earth is renewed.

We also see forms of healing breath magic. Korastrasza releases a fireball from her mouth which explodes to the ground, creating a redeemed soil - a verdant area, much like that of a druid, which heals over time. Likely, they can combine their breath spells with Life Magic (see below).

 Life Magic. Red dragons wield a form of "Life Magic" which is released in either green or red energy. It can heal their allies (living creatures) but also reveals deadly to all the corrupted and twisted forms of magic. Therefore, life magic is an extremely versatile form of magic. How do they cast it? It's not clear if it actually requires them to expend their own life or just mana. Possibly, they can do both: they can expend either their mana and / or their own life energy. It is suggested that such a form of magic was used by Krasus by combining life and magic to destroy all the sanctums.

It can be used as a beam, as a bolt, as an healing beam and even as an explosion of magical life energy.

 Lifebinder's Boom - Channels life magic in the form of a beam to heal an ally.

 

  Renew. Red dragons can heal themselves through magical abilities, such as the Renew spell (used by Narillasanz, Wyrmrest Defender). It is not clear if this is actual Light Magic or just a derivate of their domain over Life Magic.

 Flame magic. Red dragons use flames even in a defensive way, such as summoning defensive wards or barriers of... flames? How are they defensive? Possibly is some form of enchanted fire or a real barrier of flames. Anyway, they are quite effective!