A friend just gave me a very nice axe and I am getting crits that I personally have not gotten before (other then with holy weapon), earth-shaking, cataclysmic and apocalyptic! Not actually sure which is nastier:

< You slice a battle axe at an unctuous Rakash zombie. An unctuous Rakash zombie fails to dodge. The axe flashes with a brilliant white light and lands a cataclysmic strike (Shock waves ripple outward!) that elicits a burbling death-rattle as the zombie's throat is torn away.
An unctuous Rakash zombie slumps over, uttering a final gasping moan.
[You're incredibly balanced]

< You slice a battle axe at an unctuous Prydaen zombie. An unctuous Prydaen zombie attempts to evade. The axe flashes with a brilliant white light and lands an earth-shaking strike that cleaves it clean in two from collarbone to hips.
An unctuous Prydaen zombie slumps over, uttering a final gasping moan.
[You're incredibly balanced]
[Roundtime 3 sec.]

< You slice a battle axe at an unctuous Rakash zombie. An unctuous Rakash zombie fails to evade. The axe flashes with a brilliant white light and lands an apocalyptic strike (So that's what it felt like when Grazhir shattered!) that slices it clean in two to spill a rotting heap of entrails upon the ground.
An unctuous Rakash zombie slumps over, uttering a final gasping moan.
[You're incredibly balanced]

a (glancing|harmless|brushing|grazing) (strike|hit|blow)
a light hit
a good hit
a good strike
a solid hit
a hard hit
a strong hit
a heavy strike
a very heavy hit
an extremely heavy hit
a powerful strike
a massive strike
an awesome strike
a vicious strike
an earth-shaking strike
a demolishing hit
a spine-rattling strike
a devastating hit
an overwhelming strike
an obliterating hit
an annihilating strike
a cataclysmic strike
an apocalyptic strike

I don't have the full message saved for all of them, but this should highlight those random heavy hits:

as its opponent hesitates unexpectedly
but unintentionally
happening to do the right thing
leaning in an unexpected good direction
light happens to reflect into its opponent's eyes
managing somehow to improve its position
moving in an unexpected way
opponent is distracted
opponent slips slightly
opponent stumbles
switching momentum at the last minute
stumbling into a better position
tripping into a better position
while unintentionally
with bizarre luck