Help me with some nautical-themed fluff please!

So I'm working on my first xenos army, and the first one that's not also an official GW army to boot.

So far, I have a pretty solid idea for a theme, though I feel like I'm lacking some details.

After initially conceiving this idea for an inquisitor, I decided it was too much fun for just one character. Essentially what I'm aiming for is a synthesis between the mariner in Coleridge's Rime of the Ancient Mariner and Ahab in Melville's Moby Dick.

I like the idea of an Archon, driven near mad by his quest for revenge (and subsequently the ideals of revenge), but also tormented with immortality.
As he can never find his quarry, he can never be satisfied. As he can never be satisfied, he can never rest until he finds his quarry.
I also quite like the idea that, like the mariner and Ahab, all his crew must eventually die because of his actions. Because of this, I was thinking of making the Kabal comprised of former craftworlders, who don't totally belong in Commoragh, hence their nautical nature. This quite nicely makes them all atavistic and self-loathing like Ahab and the Mariner, and adds extra guilt to the Archon - He knows he's selfishly leading the last of his real kin to their deaths, but his obsession with vengeance outweighs his guilt.

I also like the "four times fifty men lying dead at my feet" part of Rime. What do you think of some kind of premonition of the Archon being stranded in the warp, surrounded by his dead crewmates?
I was thinking of this being given to him by a Harlequin shadowseer? (more on Harlequins in a bit)
I might also have wracks piloting the raiders - the crew can so scarcely afford casualties that they mutilate their fallen into functionality, so as to better preserve their dying culture and race. (gonna have some wraith constructs too because bone ghosts are wonderfully creepy!)

Perhaps his immortality is a taunting gift from his nemesis?

BUT critically, I've not thought of a suitable nemesis! I'm currently torn between a Slaneshii deamon prince, or maybe a void whale.
It might be a little mary-sue-ish, but I was thinking that whatever it was strikes at the fall of the eldar, destroying most of the Archon's craftworld, but only maiming him, and leaving enough survivors for his crew. Again, suggestions would be wonderful!

I'm dead set on an ivory leg, and harpoons galore, along with a hefty pile of raiders and ravagers.

But I'm not completely sure about the albatross. Initially it seemed simple - razorwings. But now I'm toying with having harlequins as a 'troupe of the albatross', following Mistweaver Siah as a shadowseer proxy. Like the albatross in Rime, they would be leading him to his destination. What do you all reckon?

Also, suggestions for other cool stuff to add to my army would be great! I'm still only part of the way through Moby Dick, and I'm taking my time with Rime because I really love the atmosphere.

For reference, the plan is to have
Archon
Raiders
Kabalites
Wytches
Reavers
Hellions
and then a eldar section because they're cool
Rangers
Illic Nightspear
Wraithguard
maybe a wraithlord

and again, possibly harlequins too.

Thanks for looking! And cheers for any comments, even if they are to just call me a pretentious nerd!

Make the nemesis a keeper of Secrets that effectively spawned out of one of his crew mates or his "first mate" during the fall and killed most of the others out of sheer pleasure and has since vanished into the warp turning up from time to time to taunt the archon.

On the peg leg part.

I'm fairly certain people have used https://www.games-workshop.com/en-WW/Dark-Elves-Black-Ark-Fleetmaster as an archon with some mild converting.

Thanks for the responses!
Actually, that dark elf was one of the big reasons I decided to use Dark Eldar for this theme!
Hmm, a keeper of secrets sounds interesting! I'll have a think about that one for sure!

Also, I forgot to mention! My Kabal has no name!!!
Any suggestions would be greatly appreciated! So far I've had "bitter lance" and "envenomed harpoon", but I'm not totally sold. Someone over on Dakkadakka suggested more nautical stuff, like "fathoms" which I really like, but so far nothing has really scratched the naming itch. If anyone's got a talent for that, now's your time to shine!