tricky; it's difficult to compare a lot of the puissance employed in the chronicles, a lot of the powers never come into direct conflict, so I'm left to only speculate through what is inferred in the text, or just straight-out guess ..
with that in mind, I've had a bit of a think about it, I'll give reasons where I can think of them
White Gold
Lord Foul - if he hatches plans to
use white gold and the Worm
Worm of the World's End to break the Arch of Time, it stands to reason he would survive such an apocalypse.
His diminishment post-Ritual of Desecration and after his battles with Covenant point to what a tough sonofabitch Foul is - the dude is like a cockroach, you just can't kill him.
His facility with manipulating all around him surpasses a lot of the Land's 'firepower' imo; and his lethal intentions are relentless
Jeremiah - this is based solely on the direction I think the story is going; to date his powers have been exploited by the
croyel and Foul and Roger, and those abilities have been many and varied (teleportation, his 'steam-repulsion' trick, and, post-possession, the ability to break himself free of his own autism via the bone construct).
I'm guessing that by the conclusion of the Last Dark he will have had a world-altering effect upon the Land's fate.
the Worm - anything that can eat a planet and break Time is pretty formidable.
She Who Must Not Be Named - hmmm, hard to say, She was talked up as a big-time bane, but events in AATE didn't really inspire too much fear, She basically just lumbered about all pissed-off.
Still, the text hints that she is an immortal-type in the vein of Lord Foul and the Creator, so I suppose some respect is due ..
Blood of the Earth - highly-concentrated Earthpower in it's purest form, and the most dangerous, double-edged wish-fulfillment device there is.
With the right command, the Blood of the Earth can influence anything under the Arch of Time. Just make sure you get the command right !
Earthpower - 'fuels' and informs most of the Land's magic and power.
A reservoir of puissance
Staff of Law (and by extension, the One Tree) - in the hands of the Chosen the Staff is an incredibly potent and versatile tool, she has performed countless wonders with it since Vain and Findail first hugged ... the text of the first chrons may point to the Illearth Stone being more powerful than the SoL, but I think that in Linden's hands, and with the addition of Wildwood's runes, the SoL has surpassed the Illearth Stone's might.
the Sunbane - Foul's most fiendish piece of work; the Land's degradation, along with the cruel rituals imposed by the Clave in response to the Sunbane's reign made Foul's pies de resistance a brutal assault upon the Land.
Forestals - although they were formed from the powers of the
elohim and the subsequent knowledge the forests gleaned from the elohim, their intent and purpose made them more formidable than the blase
elohim - the
elohim are no doubt technically more powerful, but their reluctance to actually get their hands dirty makes me rank the lethal Forestals higher in terms of perilousness ..
The Illearth Stone - what a horrible bane, to me it one of the most vivid parts of the first chronicles; it warped and tainted everything that fell under it's power.
Keep in mind that without a suitably evil bearer to focus it's power, Caeroil Wildwood disposed of a chunk of the Illearth Stone with little fuss at the end of TIW ...
Kastenessen - a pissed off
elohim is more dangerous than your average slacker
elohim. Fact.
Esmer - inherited all the gifts of his
elohim grandsire, with a dash of jilted-merewife rage.
Also a self-loathing
haruchai - in short, half-insane and very dangerous, to himself and everyone around him.
Elohim - meh. Still ...
Old Lords/New Lords - easy to underestimate given their inherent self-deprecation and restraint, but the New Lords collectively (and of course particularly Mhoram) overcame many of the powers I've listed through their very human qualities. Their actual ability to harness the Earthpower usually came with great expenditure to them physically.
The Old Lords were no doubt more lore-wise and Earthpowerful, but I believe ultimately the New Lords achieved every bit as much as their legendary predecessors.
the
croyel/Ravers - hard to split the three stooges and the succubi (ew, 'orrible lil' things they are, the
croyel, loved how SRD wrote Jeremiah's tormentor in AATE ..) as their primary m.o. is very similar, i.e. possession of the vilest kind.
The Ravers are probably more resilient, Caeroil Wildwood was unable to completely destroy Flesharrower and even samadhi was ultimately able to exert it's influence once again despite being 'rent'.
But I suspect the malific
croyel, seemingly independent of Foul's will, might possess every bit as much lore and sheer power as the Ravers
Viles - creative as well as puissant, it would seem. Linden felt utterly powerless when in their disorienting presence (although she was able to distract/reason with them)
Insequent - hard to say, they are measured by their individual achievements moreso than the powers they wield.
And those powers are in no way innate, they are attained through study alone.
The Theomach and The Vizard were nigh-on impossible to defeat in physical combat with their ability to slip around in Time.
and The Harrow's 'look into my eyes' trick was actually pretty impressive too, as was his ability to unbind virtually anything Vile-related (the door into the Lost Deep obviously stumped him though, and ultimately he was undone by Roger like a SUCK-er.)
Demondim - they were pretty bad-ass in Fatal Revenant, but they had the Illearth Stone to amplify their ill.
They terrified the people of the Land for an age before getting themselves extinguished during the Ritual of Desecration.
And their semi-corporeal state makes them slippery suckers to engage.
ur-Viles, Ur-Vile loremasters - we always hear of their vast lore, and the fabrication of Vain and the manacles touches upon their abilities.
But let's face it, they get taken down pretty easily when confronted by the big guns in the Land ..
caesures - they are a wrong in the Land, eating away at the Arch of Time in a cancerous manner. Able to be endured by some, and to be tamed by Linden, but still incredibly destructive and potentially fatal to the Land.
the lurker (Horrim Carabal) - scary as all hell on it's home ground turf in the Sarangrave.
Sandgorgons/Skurj - I'd rank these 'monsters' pretty equally (and possibly put the enigmatic Fire-Lions a slight notch higher than them - with the arguleh a bit below, cuz, well, they can melt like ice-creams), both Sandgorgons and Skurj are like natural forces of nature (well, natural as far as the Land is concerned) - they are destructive and volatile, but their lack of
intent beyond that destruction makes them slightly less dire than some of the other puissant beings on this list imo ... of course, Sandgorgons with Raver-remnants is another story ..
Kasreyn of the Gyre - his
geas-skillz were recalled by the Harrow's 'look into my eyes' trick.
Obviously a very learned man, clever enough to imprison the fearsome sandgorgons, but the question as to how enslaved he was by the
croyel is an open-ended one - the baddest pervert in Brathair-town that's for sure.
the
krill - more of a conduit for power than a powerful weapon in itself. But try telling that to Joan ...
Orcrest/Lomillialor - similar to the
krill, these artifacts are tools to conduct Earthpower
