Fortress

Welcome to the Fortess!
The difficulty starts to crank up quite a bit at this point. Flames everywhere. Everywhere! What are these things even? STOP setting me on fire! I will- ah, never mind!

Enemies

 * Zombie
 * Spider
 * Cultist
 * Reaper
 * Stalker
 * Wither Skeleton
 * Husk
 * Blaze
 * Piglin
 * Magma Cube
 * Endermite
 * Enderman
 * Overlord
 * Withered One (Normal+ only)
 * Fire Spirit (Normal+ only)
 * Abomination (Hard+ only)

Bosses

 * The Keeper
 * The Ghast
 * The Wither
 * The Horror

Other features

 * Local Quest: disarm 3 TNT
 * Local Trap: a bomb, dealing 1/6th or 1/5th of Max Health. Chance to set you on Fire too.
 * Color Scheme: red to yellow, plus orange.

Tips

 * Difficulty is actually getting serious now. Consider actually making up solid teams with good Relics.
 * There's. Fire. Everywhere. Bring a whole load of Coolplants.
 * Ironically, due to the very high Fire Resist of most enemies, the Blaze is not as effective here...
 * Enemy Attack and Accuracy is high, but Health, Dodge and Speed are low. You may be able to outspeed many enemies.
 * Healing is very important! Buff up your healing and get yourself some food as well.