Arcane Mage 12.1 — why it's everywhere in M+

Seeing a lot of "why is Arcane S-tier again?" in keys. Short version:

The package

• Arcane Surge + Touch of the Magi (if running that build) creates obscene funnel damage when the group stacks around one priority target.
• Counterspell at range — always valuable.
• Spellsteal weeks are free value.
• Ice Block can soak mechanics if you're brave and communicate.

What it wants

• A tank that can group mobs without running away from your Surge window.
• A healer who understands you'll stand still for 3 seconds and then do something illegal to the meter.
• Routes with big pulls — Arcane is not the "two mob at a time" spec.

Common mistakes

1. Burning Surge on packs that die in 4 seconds.
2. Not having Evocation / mana planned — going OOM mid-key is embarrassing.
3. Blinking into bad — mobility is a trap if you panic.

Full rotation notes are on Class Guides → Arcane Mage. Happy to answer build questions below — include your hero talent choice and typical key level.