The reason that Arcane Explosion was nerfed, was because mages would pull dungeons, stand there and out heal the enemies damage. Well, that still 100% possible and nothings changed, because the culprit wasnt Arcane Explosion, it was Living Flame.
Living FLAME, for some reason is being counted as Arcane Damage, thus healing for a billion.
It does Spellfire damage not Fire damage btw.
It’s intentional that it does spellfire damage, they were supposed to interact.
Though:
I was ahead of my time! They’re coming for us again 
Arcane Mages have a lot of issues they need help with but we’re just getting clobbered by nerfs first because of AoE damage to beacon being poorly balanced.
The mage healing is based off of your ARCANE damage done, says right in the tooltip. So SPELLFIRE damage should NOT be counting towards the healing. But it is, and that is the problem
Spellfire is defined by being both Arcane and Fire you twit.
Spellfire damage is called spellfire damage because it is arcane and fire at the same time.
I didn’t even think hybrid spell schools existed in classic? I’ve never even heard of it
What did they do to arcane explosion?
This is season of discovery.
Healing mages didnt exist in classic either.
Doesn’t it have a minute cooldown? How is this an issue?
Nerfed healing by 80% yesterday. It’s still ok if you’re hitting a large number of targets, but not as OP as it was before.
That doesnt matter, the issue at hand is they nerfed Arcane Explosion thinking that is why mages could pull entire dungeons and just out heal the damage, but its Living Flame that is causing this.
Theyre quote was “We didnt intend for mages to trivialize content”
Well im watching streams of mages pull all 60 mobs in deadmines at once and stand there and face tank it.
Bandage-weaving Mages would like a word.
As long as they rebalance Arcane Mage healing a bit, nerfing living flame would be a good thing. The nerf to Arcane Explosion was extreme overkill. It’s not even worth pressing unless you have 12+ mobs at this point. Outside of living flame arcane mage healing feels quite limited, so I’m a bit nervous if they give living flame the arcane explosion treatment. Could end up having a rough time solo healing dungeons.
Frostfire Bolt?
Existed at least as early as TBC, some mobs in Sunwell could do Plague (Shadow, Nature) damage. Not sure about Vanilla.