Sorcerer… Cyborg???

Kothar summoned a portal directly in front of himself, and then another within the center of the vertical tunnel. He stepped back, and ran into the portal, for he would need to ensure he had enough vertical momentum to be able to reach the rungs on the side of the tunnel.

Kothar ran forward, phasing through the portal, almost slamming into the side of the tunnel, just managing to break his sideways fall by quickly grabbing at the rungs that grew out of the gray wall like natural extensions of it. 

But from here on, things would be even more difficult, since Kothar was within the narrow vertical tunnel, his body would want to fall back down toward the ground, so he would have to have enough horizontal momentum to prevent himself from falling into the portal as he passed through, losing parts of his body to the void.

Kothar awkwardly turned himself around clutching the rungs awkwardly  with his arms behind himself, next, he opened a portal in front and slightly below himself, he would effectively be stepping down into midair.

Kothar opened the next portal, high above himself, glancing up to make sure it opened in the correct location. 

[Wait a moment Kothar, if the ship falls again, your portals would become fatal traps.] Silane warned, the ship hadn't fallen again, but for Silane, even the slightest chance was a significant danger.

[What other choice do I have?] Kothar responded, flexing his legs and launching himself away from the rungs, falling a little as he came out of the destination portal, flipped around in the direction, facing the rungs of the tunnel again.

Kothar grabbed the rungs, halting his fall, and took a few deep breaths, before turning himself around to repeat the process.

Even moving so awkwardly, Kothar's enlarged Spatial Core as well as the increased familiarity he had gained with Spatial Mana while suing the Spatial Artifact meant that using his portals to travel through the ship was far faster than slowly climbing up the maintenance shafts.

Kothar repeated the process, over and over, and then, passing bay other horizontal shafts, ignoring them to continue his upward climb.

But after about five minutes of repeating this process, the monotonous process was broken, as a vibration travelled through the enormous ship, Kothar feeling it in his hands as he tightly gripped the rungs.

[Stop! Don't portal just yet.] Silane called out, as Kothar gathered his Spatial Mana to open another portal. 

Her warning was well timed, and the ship suddenly sank, sending Kothar flying upward, as it plunged downward. From the outside, an observer would have seen the enormous craft dip the slightest amount, a subtle shift in its positioning. 

But that was only thanks to its enormous bulk, this time, the ship fell for kilometers, plunging uncontrollably downwards.

Immediately, as he felt the ship shift beneath his hands, Kothar let go of the rungs, allowing the ship to fall down around, sending himself up what felt like an endless climb.

[A few more of these, Silane, and we'll be at the command center in no time.] Kothar joked, as the ship came to a stop, reaching out to grab the rungs, stopping himself form falling back down and wasting the progress that he had made.

Kothar continued upwards from almost an hour, opening portal after portal, occasionally being boosted upwards by the ship falling, as it continued to do so at regular intervals, Kothar avoiding any near misses with his own portals.

Soon enough, the upward tunnel came to a halt, the pipes disappearing into the gray material around Kothar, the black inscriptions within faintly visible in the dim yellow glow.

[What now? Looks like we're out of the tunnel.] Kothar said to Silane, almost opening another portal out of habit. By now, his nosebleed had stopped, and Kothar had replaced his mask. Over the past weeks, he had grown fond of it, feeling more comfortable wearing it than not.

[It shouldn't be too far now, all those falls made things far easier for us. Just climb back down to the closest horizontal tunnel, there ought to be one close by, we should be able to find our way from there. Be careful though, don't be too hasty, we don't want to be setting off any alarms. I don't think there'll be too many maintenance workers up here, but there's sure to be a lot of guards.] Silane warned, as Kothar climbed back down the shaft.

Sure enough, there was a horizontal tunnel waiting for Kothar as he climbed down, Kothar jumped from the rungs to the vertical tunnel, his arms and back aching and tight from constantly pulling himself out of falls each time he passed through a portal. 

Kothar only walked a few meters along the new tunnel, before Silane stopped him.

[Right here, just push on the wall.] Silane highlighted a section of the wall, and with the same satisfying click as before, the wall swung inwards, and Kothar hopped out into a wide tunnel.

The tunnels toward the top of the ship were far more spacious than all those Kkothar had seen elbow, there were wide enough for at least fifty men to march abreast, and were well lit, with the entire ceiling thick with the hollow see through tubes of yellow fluid that lit the ship.

Here, the inscriptions were thick on the walls, and Silane was silent, as she took in what she was seeing, processing it to find the best route to the control center.

[Go right.] She said, mostly occupied with deciphering the inscriptions all around them. Since the inscriptions seemed to both be utilized as a language, and as a kind of circuity for the living machinery, it was difficult for Silane to puzzle out the meaning and purpose of it without any reference.

Kothar turned to the right, and far off along the tunnel, he saw a hulking silhouette moved through the light. 

Just as the heart had been guarded, so too were the tunnels at the top of the ship.