You're looking above at a series of four doujinshi that together make up a fan sequel (not by Akari Funato) to Vheen Hikuusen Monogatari. The drawing is very rough, but the story, while altering VHM's plot in a couple respects, is an interesting and thoughtful consideration of Silver Star's events from another perspective that includes some very prescient character moments. (I wrote a very lengthy two-part synopsis of the series here and here if you're interested, and I am gradually working on translating the books.)
The story's not why I'm writing now, though. The title of the work is Ama no Kairou, or Heaven's Corridor. More probably Corridor to Heaven, or Corridor to the Heavens, though strictly speaking, that would be Ama e no Kairou. (Ama can also mean "sky," which obviously has its own relevance to Tales of the Vane Airship, but I think the more poetic interpretation is more apt.) The phrasing of the metaphor seems somewhat odd, but the intent makes sense, given the time in Ghaleon's life it depicts (his life post-KSK up to his challenge to Althena and death).
Right, so I was reading The Obscuritory, a very worthwhile website dedicated to obscure and intriguing PC games, and I noticed an interesting bit of text in an article on Comer, an ambitious yet extremely rare adventure game self-published by a Hong Kong dev:
As one of the commenters on the article notes, the large text on the side also translates to "Heaven's Corridor," and it uses almost the same text: 天國の走廊 instead of 天の回廊. The commenter notes that 走廊 is the Chinese version of "corridor," while 國 is the classical version of 国 (天国, or tengoku, being the more common word for "heaven"). The character の is Japanese-native, though Wiktionary is telling me it's sometimes used to add a faux-Japanese flavor to Chinese text. In any case, this Hong Kong developer felt inspired enough to go out of his way in what is reportedly otherwise exclusively Chinese & English box text to use a mix of Chinese and Japanese, or at least Japanese-flavored Chinese, to express...this same odd metaphor from the doujinshi.
So I took to the search engines, wondering if this was some sort of reference I was missing. 天國の走廊 (and 天国の走廊) brings up only the Obscuritory article, but 天国の回廊, a slight alteration from the doujinshi title to more common verbiage, brings up the Chiostro del Paradiso—the Cloister of Heaven—in the Duomo of Amalfi, whose name in Japanese is, evidently, "Tengoku no Kairou." The Chiostro apparently serves as the graveyard for Amalfi's nobility, though looking at photos, I'm hard-pressed to answer where, exactly, the nobles are buried. Maybe in the walls. The Chiostro's purpose, however, would suit its invocation in both the Vheen Hikuusen doujinshi, dealing with the demise of the magic-race "nobility" of Vheen, and Comer, which evidently deals with the long-futile efforts a succession of historical geniuses (Einstein, da Vinci) to solve "an ancient puzzle that will determine the future of humanity" and leads to a sea change in the planetary status quo. Still unanswered, though, is how Amalfi's Duomo got boosted to such visibility in Japan (and Hong Kong, I guess).
The Wiktionary definition of "cloister" notes such structures in religious architecture often showcase stations of the cross, which would be in line with all the Ghaleon turmoil in Ama no Kairou on top of his canon tragedy mire.