Lysander

@Sieben You need to hit four switches all near Cuvar's position in the right order (top-left, top-right, bottom-left, bottom-right), then go to the upper left and around to hit a fifth switch to finally open the chamber where he's hiding. @toshiki747 You need to use the Warp spell, or the warp trap panel at the upper-left-hand side of the map. If you combine Warp with Teleport + warp trap (to keep using the trap over and over without walking to it), you get 20 chances each visit to the Dragon's Nest, but it's completely random which area you'll land in. It's worth noting though that I only ever got flowers from any of the chests on that floor, and I ran it multiple times to get into all of the hidden areas just to be sure. There may be rare items possible, but I never got any or dug any further into it. Also worth noting, if no one has done so yet, that there are no CGs which require Darx to land the last hit, despite multiple references on this and other sites that suggest so. I played most of the way through my 2nd playthrough grabbing only party boosts, healing spells, and warp/teleport spells, meaning Darx killed zero enemies (not "a small number", but actually zero), and I still got most of the prison events and Cass / Ayaka events before starting to actually use Darx for offense in battles. Lastly, I keep seeing questions about the most efficient way to get the Cass / Ayaka events, and the fastest way I've found involves the Garden Lair B2 (I used the "Defense- Punish the Intruders" mission, but it shouldn't matter) with a Box of Light equipped and two Hawk Feathers in your inventory, or some combination of those (I haven't tested with less). Save just before entering the map, and you'll be able to see the yellow dot on the red staircase in the bottom right room immediately, if one exists. If there isn't one there, reload from the save game, re-enter the map, and repeat until you get one. Use Teleport to get to the dot instantly when it shows up, and if it's not the one you want, go into Options -> Return to Title and Load from the dialogue popup before the battle, as it's a bit faster than actually fighting. No yellow dots will appear in this map except Cass, Ayaka, and Tatsumaki, assuming you've released the princess back to the surface. In my experience, I found one every 15 tries or so (some took over 30, while others happened back-to-back... just luck of the draw), with each attempt taking only about 10 seconds once I got in the rhythm of it. I got all of the events within maybe an hour. Good luck!