Valor: noticeably more effective on the flying skull than its glass replica.

Recall Potion: claims it transports him instantaneously to his 'starting point', which from context and vague implication seems to be the place where he met the helpful NPC.

Flying skull: able to float through blocks, but very slow and easy to kill before it gets near him.

He can feel the skulls when they're floating through his blocks, so he's not too worried about them sneaking up on him.

He keeps one Recall Potion on hand just in case, and starts using Valor because it's more efficient.

Onward.

The tunnels wind down, and down, and down. Occasionally they branch. Armored skeletons and purple slimes frequently attack.

There are other hazards, too.

Like the invincible burning saw blades that come rolling over the walls, ceiling, and floor - easily avoided by simply stepping out of their path, but impossible to damage: to kill one, you have to immobilize it and wait for it to vanish. It doesn't even have the decency to drop any loot.

Or the invincible spiked balls that swing in circles on the ends of chains. Those ones can pass through solid objects, but the points around which they swing are anchored immovably in place, so all he has to do to avoid them is not get in their way.

He is surely not about to step on any Pressure Plates he detects on the floor, particularly not if there's a Dart Trap embedded in a nearby wall. The connection between these objects is not apparent, but there's bound to be one.

And then there are the robed skeletons that teleport from place to place and fire water-like projectiles. Those might be scary, if it weren't for the fact that their projectiles disintegrate immediately on contact with any sort of barrier.

It is simple enough to follow a path that does not intersect these hazards. For extra safety, he forcepatterns so that he can't walk into them before he gets anywhere near. (He tries to claim the saws and spikes to use their motion as power sources, but finds that they are not really there. It reminds him of those feathers that were thrown at him before. Oh well.)

He has two spells, one firey and one watery. Are either of them particularly effective against the robed skeletons? If not, he has a yo-yo and he's not afraid to use it.

In that case he will find it largely trivial to explore the rest of the Dungeon, killing monsters and looting chests as he goes.

For the most part this is a straightforward accumulation of large quantities of loot, but it turns out that there is also an NPC sitting on the floor of a side chamber, tied up with rope - she appears when he gets close but before he has direct line of sight. Something should probably be done about her.

Of course he rescues the girl, that's just what you do. Offers of marriage, et cetera, will be declined.

He walks into the room, but by then he's already claimed the rope from where an end trailed on the floor. With a completely unnecessary wave of the hand, the untied rope flies away from her body.

"Thanks! It was only a matter of time before I ended up like the rest of the skeletons down here," she dialogues, getting to her feet and dusting herself off in a sequence of movements that somehow give off the impression of having been prerecorded. Then she wanders off into the tunnels.

If she wants to get back to the surface, she is going the wrong way.

Presumably if he was supposed to talk to her she would have stuck around or asked him to follow.

He checks the tunnels in her vicinity for any surprises to change this estimation (nope), then finishes cleaning out the tunnels of monsters and monster loot. Anything obviously permanent can just be claimed for later.

He climbs out of the dungeon and flies to his village. Were his defensive measures adequate, or will he have to fix things before he gets some sleep?

While he is en route back home, the rescued NPC teleports from the dungeon to an apartment on the same floor as the helpful NPC.

His village is unharmed. Monsters only seem to show up at a certain approximate distance from his physical body, and they disappear when he gets too far away; the village has had a pretty peaceful night while he's been Dungeon-delving.

If things are peaceful when he is away, maybe he shouldn't be here.

He moves out of monster spawning range, then stacks up blocks until he can build himself a little floating temporary house out of blocks. Remove pillar. Shape bed. Zzz.

The eyeballs don't disturb his sleep as much as imagined skeleton arms that pass through walls.

But he's not on anyone else's schedule. He keeps his bed-room-house dark until he's gotten as much sleep as his body wants.