Spoilers may follow.
I entered B20F and began exploring for the first time, prepared for a climactic boss fight and all sorts of nasty enemies. So I was entirely unprepared when I saw that the map was crawling with FOEs. A cautious adventurer would have immediately warped back to town, sold the golden chimes and items taking up space in his inventory, and stocked up on Amrita's, Nectars, etc. That's not how Guild Ardent goes about the Yggdrasil Labyrinth. No sir. Guild Ardent works with the situation on the field. When combat is a viable option, it fights. When combat is an unattractive option, it flees.
Through some careful maneuvering I managed to avoid the FOEs and explore the floor. Surely there had to be more to the floor than just a herd of bosses. Where was the menacing black ball? I became careless. A FOE saw my party, and its icon became red. I hadn't explored the map enough yet. I didn't understand its layout and the patterns of the FOEs. So I ran. I ran away from that FOE half-way across the map. And soon that one red icon amongst a sea of purple became a mob of red trailing me. But there were no normal encounters on the map. I was safe. I could run forever. That is until I got trapped between the chasing throng and a normal patrolling FOE. Oh well. How bad could it be? With so many, it must be a collection of minibosses. No problem.
Oh how wrong I was. Those enemies were just as strong as any FOE. As soon as one fell, another stepped in to take place. After all, I had managed to enrage pretty much every single FOE on the bottom portion of the map. If I recall correctly, the battle took over 60 rounds to conclude. At first I was hopeful. My medic had immunize up, and things were going well. Then I began to run low on TP. My alchemist had rested recently, and although he was capable of pulling his weight, his TP levels were low. Soon he became useless. My Protector quickly burned through her TP using the costly Smite. And maintaining immunize on the party had its toll on my medic. As mentioned before, I hadn't prepared for such a long fight. I began to run low on amrita's, and decided that only my medic should keep them, since only the constant use of Immunize was keeping my party alive through the gauntlet. Towards the end I actually had to dip into my reserve of Hamaos which I had found in treasure boxes and could not buy in town.
My protector and alchemist began to use physical attacks, leaving my survivalist and dark hunter to deal damage. The survivalist was doing well with Apollon, until she died when I forgot to Immunize for a turn. Every time I revived her she would die before I could get Immunize back up on her. It was all up to my dark hunter, who had once been dead weight on my team. Sure he did decent damage and was fast, but he didn't have the burst power of Apollon, or the survivability of my Protector. But in that battle I learned to appreciate the fact that his whip attacks cost only 5 TP. That's pretty cost effective in comparison to skills like Smite.
I ended up defeating the last six or so FOEs using physical attacks and whip skills. My team, battered and bruised, drained of their energy, their hoarded stockpile of emergency items depleted, went back to town and took a well deserved rest in the inn. When I returned to B20F, the FOEs were back.
My soul shattered. I sat, stunned and immobile. And then I went about the grim task of defeating those FOEs all over again.