Why Dark Souls 3's Aldrich is 2016's best boss

Warning! There are plentiful spoilers ahead for all Dark Souls games.]

You'll meet his acolytes first – giggling ogresses in matted, sagging corsets, their belts jingling with torture implements, and red-cloaked porters who shoulder cages full of chopped-up bone and flesh. Deep in Undead Settlement – an area you'll reach, in a portentous reversal of a key moment from the original Dark Souls, when two gargoyles carry you down the cliff from Lothric Castle – you'll find rooms hung with carcasses, neatly bundled up in sackcloth for transportation.

Beyond that there's the Road of Sacrifices, with its mutant carrion birds and its lone madwoman in rags armed with a butcher's cleaver, a road that takes you via the Crucifixion Woods to the grounds of a befouled cathedral. And then there are his rings, obtained from the colossal fusions of wolf and spider which haunt that cathedral – magical artefacts that impart a little of the master's terrible hunger to the wearer. Aldrich, Saint of the Deep. Aldrich the man-eater.

There are many wayward Lords in Lothric – the Princes sulking in their tower, the Abyss Watchers engaged in an orgy of self-destruction – and there are certainly more involved boss fights. If I had to pick a favourite, it would probably be the Dancer, a sinuous, silvery giant whose footsteps ring like the strokes of a clock. But it's Aldrich who tantalises the most, Aldrich around whose unholy cravings so much of Dark Souls 3's society and geography is organised, and Aldrich who is the focus of the game's shift, following PlayStation 4 exclusive Bloodborne, into the realm of the macabre.

You'll spend much of the game working your way towards him - an increasing and unnerving closeness, whereas Yhorm and the Princes aren't much of a presence till you actually enter their domains. You'll glean bits and pieces from dialogue and item descriptions about the object of Aldrich's faith – an oceanic metaphysical plane that may be no more than a reworking of the Abyss from Dark Souls, but which is possessed of life of sorts, festering and corrosive where the Abyss is airless and still. It's suggested that Aldrich's cannibalism has become a sort of parody of the Catholic Eucharist, an attempt to concentrate the "dregs" or heaviest elements of a human life in his own flesh, and so descend further into the belly of the Deep. But the key motivation is simply appetite, and the Church is to some degree just a mechanism of containment, regulating Aldrich's diet at the command of the self-appointed Pontiff Sulyvahn.

That's certainly the impression I got on making it through to Aldrich's coffin, a building-sized cube of ribbed stone that is more of a nuclear waste disposal silo than a tomb. Aldrich no longer, it turns out, resides in the Cathedral – in a nicely judged thickening of the plot, he has departed for Irithyll in the Boreal Valley. Or at least most of him has. While fighting robed deacons and their servants you'll encounter sloughed-off, animate gobbets of the Lord's own flesh, left to wallow in pools of filth beneath the feet of imprisoned giants.

It's important to see all this in the context of developer From Software's and Hidetaki Miyazaki's preoccupation with consumption more generally. Dark Souls, after all, is a series in which you ingest souls to enhance your abilities, and its key antagonists are essentially gluttons - creatures that have partaken to excess of various forbidden energies or bloated themselves on the misery of their subjects. Unwilling to embrace a long-overdue death, they must be forced to yield up all they have assimilated. And when the original game ends, your character is asked to do likewise – to sacrifice yourself and all your accumulated gains to the First Flame in order to prolong the world as is.

This is a meditation on the costs of unnatural longevity that can't help but extend to the act of sequel-making. Miyazaki never breaks the fourth wall as overtly or ornately as, say, Hideo Kojima, but his games are littered with uneasy references to the idea of building on a formula. One that occurs is the presence of an enemy from 2009's Demon's Souls in the Painted World area in Dark Souls – a nod to the game that started it all inside a representation, inside a representation. Cannibalism may be the developer's most pointed exploration of the parallel yet. If the idea of giving to the flame represents a clean break, an act that transforms by destroying, to be a cannibal is to congest yourself with the grossest elements of the past. It's the sickliest kind of iterative thinking, not just “milking” your inheritance but chewing it over in hopes of a fresh start, and those who are partial to it are, this game suggests, destined to a sticky end.

Confronting Aldrich means tackling these anxieties about the very concept of a “creative franchise” head-on. Having negotiated a catacomb's worth of hyperactive skeletons and survived a brush with Sulyvahn, you eventually find the Lord at the summit of Anor Londo – the city of the gods from the original Dark Souls, now reduced to a dank and slimy shell. It's here that you make the game's nastiest discovery. In a ghastly spin on the Ancient Greek tale of Chronos swallowing his children, Aldrich has cornered and eaten Gwyndolin, last and frailest of the gods.

As sorry as we may feel for Gwyndolin, however, it's possible to feel a certain amount of pity for his killer. Engorged with the dregs of hundreds of sacrifices, Aldrich has become formless - a rancid, room-filling swamp of rotted fibres and bone that wields the husk of Gwyndolin like a puppet. The Lord's fate in seeking to digest the essence of others is to lose his own. His attacks are warped echoes of Gwyndolin's spells and abilities, the battle's very soundtrack a mash-up of Gwyndolin's score and that of Nito, First of the Dead, another boss character from Dark Souls 1. His tactics are crude, sloppy, enveloping – a mystic arrow bombardment that chases you around the chamber, a defensive hail of homing Soul Masses vomited up whenever he takes damage, a sprawling cloak of fire when his health falls below a certain level.

Having gulped and guzzled his way to the summit of the Dark Souls universe, Aldrich has become the empty centre of his own mystery. If the fight can feel anti-climatic – it unfolds in the same area as the amazing Ornstein and Smough clash from the original game, and isn't nearly as accomplished – that's entirely in keeping with the theme.

Whether you buy the little meta narrative I've put together or not, Aldrich's story is gloriously ghoulish, the kind of steady playing-out of a revolting prospect I'd love the developer to try more often. There is a dreadful, enticing ambiguity hovering over the actual practice of his cannibalism, helped along by the deftness of Dark Souls' English localisation. We are told that he “slowly devoured the God of the Darkmoon”, a process that sounds relatively painless, more absorption than consumption. But we are also told of other sacrifices that he rejoiced in “imbibing the final shudders of life while luxuriating in his victim's screams”. Is this the activity of an amoeba, slowly disintegrating its subdued prey, or a work of Hammer horror – crunching, ripping, tearing?

I'm not sure I want to know. The elusiveness of From Software's writing is integral to the success of its world, with so many possibilities left to skitter around the periphery of your vision, even as some frightening object veers into plain view. The only game that does this kind of devilish hinting better, for my money, is Failbetter's Sunless Sea, with its “Unaccountably Peckish” trait and the toe-curling option to “feast!” when your supplies run low.

Once such a shot out of left field, the Souls series is at risk of becoming one of the industry's gilded fixtures. The list of imitators runs long, and if Dark Souls 3 is a tremendous game it's also one that extends and expands rather than transforms. Characters like Aldrich, however, suggest that not only is Miyazaki well aware of the perils of diminishing returns (he has suggested that this will be the last direct Souls sequel) but that Souls is still capable of meaningful growth – away from the stately and sorrowful abominations of the first Dark Souls, and deeper into the vein of body horror opened up by Bloodborne. 2016 has given us many monsters. Aldrich, at least, is a monster I can admire.