Greetings, all! I'm playing 8.1.0 New Content Edition. I'm already in the Temple Nodes. I visited Nulb. Where is this Arena of Heroes of which the post speaks, and how do I reach it?
You need to complete Welkwood Bog which you get by first speaking to brother Smyth in Homlett, then speaking to the man in the bottom left most house in Homlett. The man Jinnerth the Tailor wants you to talk to for his quest to join the militia. After you complete Welkwood bog you might need to wait 8 hours. A chest appears next to brother Smyth which requires a very high open lock skill. I think a minimum of 15? If you can open it then you get a book which transports you to the arena after reading it. Be warned, some of the enemies you face can be tricky. First three owl bears. Then two skeletal hill giants. Then for the final mission 3 Undead Wizards; 2 Skeletal Hill Giants, lots of ghouls and zombies. If you have a cleric with very powerful turn undead then it's way easier. But the Wizards and Hill giants can mess you up if you are unprepared.
From the walkthrough guide: The Arena of Heroes becomes accessible after you have been told of Nulb. Talk to Brother Smyth (Blacksmith) in Hommlet, and tell him that you are "looking for something different". Brother Smyth's chest appears on the ground when story state 3 is reached (i.e. you've learned of Nulb). You need to open the chest and read (use) the book inside it to enter the Arena of Heroes. Brother Smyth's Treasure Chest (Open Lock DC: 34) (this lock cannot be opened by the spell Knock)