Delusion is one of the six ten masters released. She's one of the easiest to still acquire, the other being Baochuan, but I would advise you spend the $50 elsewhere, because Delusion is the worst of all ten masters. Allow me to explain.
First, I must first evaluate her abilities and statistics. At 7 cargo, she's plenty capacious, but she lacks speed, and her armament is subpar for a ship of this size. Her abilities and keywords play into Fitzgerald's obsession with gold, but ole Fitzy's ability is not especially useful, considering the fervor with which enemies will avoid boarding confrontations against ten masters. The fact that he doesn't really take up any space due to his link doesn't help the general lack of utility of his keyword.
Looking back to the ship's own abilities, we're confronted with a number of interesting looking abilities that don't seem effective upon further examination. Eternal, despite being a solid way to protect the biggest investment in your fleet, means that you'll spend ten frickin' turns repairing at your home island, provided no extra actions are available. Eternal can't be used as a shortcut to bring your gold haul home, either, so it's only of use as protection to this ship alone.
Filching Gold, as is with Fitzgerald's ability, is of minimal use on a ship so large, as foes will avoid making contact entirely, limiting its defensive ability. The ship's lack of speed makes it tricky to use offensively, too. Likewise, because Ghost Ship does not allow you to finish your turn atop terrain with immunity, Delusion's poor speed and tremendous size makes this ability almost useless.
Unholy Light is of some interest, but the limited range (and availably of the same ability on the cheaper Specter) makes it hard to justify the use of this ship to access this ability alone. A combination pointed out in my review of Raven's Neck with Devereaux allows for an island scan half as effective, but the unlimited range means it doesn't rely on proximity.
Because of her unfitting abilities, her raw stats must be relied upon for success, but as outlined above, her only attractive trait is her hold space of 7. Similar cargo capacity can be achieved on far cheaper ships, like La Joya del Sol, which also has a higher base move. Her speed is such that a helmsman is a necessity, so her deployed cargo space will never exceed 7 anyway, so the gain of a marginally faster move and lesser cargo space when compared to a ship a third her price is embarrassing.
While she does have the benefit of a ten-strong roster of guns, they are mixed between rank 3 and 4, so she absolutely needs a world hater to be effective as a warship, but that cuts into her cargo space, doubly so if you go the Cavendish route and utilize multiple versions of the world hater ability to boost cannon rolls by 2. Extra actions are almost a necessity if this ship is to be played in an offensive role, too, due to her underwhelming speed, even with a helmsman aboard.
She can be played in a hybrid role, but ooh, you're restricting yourself to a handful of crew to save space for gold, should you choose to set up Delusion for this role. Fitzgerald is probably best left behind, since he's costly, but adds next to no value.
So, how do you best set up Delusion for each of these roles? Gold runner, warship, and hybrid?
Gold: Helmsman + Oarsman + Explorer or El Fantasma
Warship: El Fantasma + Helmsman + Captain + Devereaux + Oarsman
Hybrid: Captain + Helmsman + El Fantasma + Oarsman
R̟̤̬̩ ͔̀E̟̼̹͇͙̲̭͠ ̖A̖ ̧̺̹Ḽ̖͚̲͈̺̗͞ ̖͢S̼̲͈͕ ̡H̦̠̥̻ ̮̹̣̮͎̗̮I͓̮̮͕̩̫ ̪͉̙̬̗ͅP̻̹̤̲̤: Cavendish + Griffin + Hermione Gold + Kian Ng + Crimson Angel + Brent Rice + Commander Albert Crenshaw + Wayne Nolan + Oarsman
There are other cursed crew I'd love to find a use for, like some of those outlined in this thread, but some of them need special fleets built around them, and Delusion's too generic to support any of these crew well.
As for the best way to counter Delusion? Pick anything that's faster, or just more budget-friendly, and you'll beat it. Quick gold runners will empty islands before she can get to them, and speedier warships will always get the first strike.
Durable, capacious, glows in the dark.
Expensive, unfitting abilities, hard to set up effectively, almost infinite number of options better suited to any role you want to use her in... save for pretty glowy ships.
Artwork and aesthetics:
Unfortunately, the copy I own seems not to glow in the dark very well. It's something you will only ever check out once or twice anyway, since nobody plays games in the dark. Aside from that, the ghostly grayscale makes her one of the coolest looking ships on the board every time she's used.
Overall rating: 4/10. She is acceptable in her role, but she's so gosh-darn expensive that she becomes borderline impossible to use in small games, and not cost-effective enough to use in larger games.