Blackfire Basin is a 12 vs. 12 Scenario in Tier 3 Greenskin vs. Dwarf (Black Fire Pass). That is only accessible during the Blood Basin Live Event, during this event the scenario is open to all tiers.
This Scenario features classic Capture the Flag mechanics just the way Greenskins and. Dwarfs like it - head-to-head! Each Realm must break into the opposition's "base" and take the enemy's banner back to their own base. The flag locations have three points of entry either by gate, broken gate, or super secret side paths (okay, they're not really super secret, but they're not blatantly obvious either). "Smash and grab" as they say, and get the enemy flag!
Spawn points for this Scenario will overlook the flag location so players can gather their forces together before charging out to defend the flag or assault an enemy location. Going straight through the map, across "Deadman's Del", will get you to the enemy the fastest, but this leaves you wide open to be hit from all directions. Try cutting to the east or west and take those afore mentioned side paths for a more protected route into the enemy base.
Black Fire Basin is a classic CTF map, which means kill or be killed. If you let the enemy take your flag, you're going to fall behind quickly. If your Realm sits back on defense the whole time, you may actually win the kill counts, but if the enemy manages to capture even a single flag, you're more than likely going to have to play catch up. Mass flag rushing will be common place and expect this Scenario to result in some truly bloody battles! Oh... and don't mind the big frozen "fish"... he's simply out of his cave.
If anyone knows what the hell that fishthing is, please share, it's an huge thing.