Losing is fun. Corrupted equipment is not.

Or you can just not care - unless you are really "unlucky" he'll hit you with corruption about half a dozen of times though the entire fight with him. That's not enough to wreck you too badly considering it's the final boss so defeating him while half-dead and with your items falling apart still counts.

In fact, there is at least one person who defeated Dredmor at the same time as dying themselves. Now that's an achievement.

 

I beat him up a few days ago, and I have to admit I was very disappointed by the ease of which I could do so.
I had about 200 Clockwork Sawblades handy to whittle him down with, but after about 10 it was increasingly clear I was lopping limbs off by the throw. I Charge'd Of The Steam Brigade in there, and he almost died instantly. It was glorious, but definitely not reflective of how difficult it was to reach him in the first place.

I reloaded my save and put on my AA gear again rather than my MR focused gear, charged in without using any Clockwork Sawblades and did indeed not see any discernible impact of his corruption.

 

Ah, yes, the sawblades. The second strongest thrown weapon (after the puffballs).

Come to think of it, didn't Digula and the Diggle Hell in general get added because it had been accepted that the end-game was a tad to easy as far as Dredmor himself was concerned...


But yeah, Dredmor's corruption is here pretty much because "the game has corruption and he's the final boss so whatever", not to make it into something truly debilitating.

 

I distinctly remember almost flipping my shit over how tough Digula was after how easily I beat Dredmor the first time around

Crap, I didn't save my last build to try out Digula. Damn!

 

I simply changed the corruption spell in spellBD to not do anything. As a DCSS player especially I don't like tedious, turnless equipment swapping that completely bypasses a game mechanic. I'll replace it with a 100 turn infinatly stackable debuff that decreases all primary stats by 3 or something when I get around to it so corruption will actually do something very dangerous. Dredmor casting corruption on you isn't really that dangerous because he is only on monster in the entire game that you fight at the very end of the game so any permanent damage he does might as well be temporary because it goes away when you defeat him anyway.