To me, The Spell is the thrashiest by far.
Seven songs deep into the album and this is my impression as well. Doesn't even sound like death metal anymore.
EDIT: Next batch of autism
Conjuration of the Spectral Empire (2002)
Traveling Through Chaos (I, the Pastfinder II) - 4.5/5 (see Brand except better fused and now it actually works, some gorgeous wall-of-sound stuff too, harmony leads at 6 minutes and that bass line underneath are giving me chills)
A Soulstorm Bleeds Over the Horizon/Procession to the Infraworld - 3/5, 3.5/5 (instrumental intro former, spacey lead stuff) (instrumental, something about opening a lengthy album closer with a simple galloping riff always gets my dick hard, unfortunately it's kinda meandering around after that, I was expecting some One Shot at Glory-tier shit but this is still pretty good, especially the second half)
Deathcult Arrival - 3.5/5 (instrumental, that Darkthrone-sounding riff 2 minutes in is awesome, strong riffing all the way through)
The Conjuration - 3.5/5 (very '93 At the Gates here, riffing a bit pedestrian at times but the melodies push it up)
Brand the Mournful Liberation - 3/5 (waltz-y romantic Chasm for the first half, goes neoclassical Destruction-style for a bit after that, I should love this in theory but the rhythms are too bland, lacks the necessary propulsion that songs like In Superior Torment offer)
Dark Cloud - 3/5 (intense)
Reveal the Truth - 2.5/5 (average Slayer/Morbid Angel-y death/thrash)
Master of the Arcane Torment - 2/5 (that main riff is actually bad, it's like they tried fusing a basic thrash rhythm and a basic USPM rhythm and kept only the wrong elements of each, the other parts are typical but the solo section is very good)
The Ecstasy of Pain & Destruction - 2/5 (thrashy but boring, sounds like a weak Protest the Hero song with Darkthrone/Chasm dissonance tossed on)
The Spell of Retribution (2004)
Conjuring the New Apocalypse - 3.5/5 (another thrash song but they finally tried some new rhythms, the Metallica break halfway through was pretty sweet, some lurching epic parts too, closes with some Dark Angel punctuated double-bass and chop, this is what the entire album should have aspired to be)
Remains of the Covenant - 3.5/5 (melodies are really layered here, some Helstar vibes)
Eternal Cycle of Delusion - 3/5 (did the production change here? it feels like they just repeated earlier ideas in the album but made it a bit louder and heavier to fake a meaningful album climax, the Destruction-style parts are nice though, that tech-y thrash riff 5 minutes in was cool until they unnecessarily filled out the pauses)
From the Curse, a Scourge... - 3/5 (instrumental, some neoclassical wank, giving me bro metal vibes)
Retribution of the Lost Years (I, The Pastfinder III) - 2.5/5 (some good parts but too slow and long)
The Eclipse: Monument to the Empire - 2/5 (boring melo-whatever, on occasion it feels like it's going somewhere meaningful like around 6.5 minutes in but most of this is Schuldiner-tier rifflessness)
Manifest My Intervention - 2/5 (first couple minutes were good, at first bordered on self-plagiarism but began moving in a new direction, but then in came all that dut-dutalutdut Testament/Protest the Hero riffing)
Fortress - 1.5/5 (yeah this is basically indistinguishable from any modern thrash/"melodic metalcore" band, total bore, should have been a 3 minute song tops)
Conqueror & Warlord - 1.5/5 (pretty rigid, that first riff is disgusting, rest is just there)
The Omnipotent Codex - 1/5 (force-fed too-many-notes meloblack shit, obnoxious and Emperor-tier)