Increase the damage just a bit to compensate and bam, this:

(Active): Darius leaps to target enemy champion and strikes a lethal blow, dealing true damage. For each stack of Hemorrhage on the target, Noxian Guillotine deals an additional 20% damage.
The cooldown is refreshed if Noxian Guillotine kills the target, or if the target dies within 0.5 seconds after use.

Cost: 100 mana
Range: 475
Cooldown: 100 / 90 / 80 seconds

True Damage: 160 / 250 / 340 (+0.75 per bonus attack damage)
Maximum True Damage: 320 / 500 / 680 (+1.5 per bonus attack damage)

becomes this:

(Active): Darius leaps to target enemy champion and strikes a lethal blow, dealing physical damage. For each stack of Hemorrhage on the target, Noxian Guillotine deals an additional 20% damage.
The cooldown is refreshed if Noxian Guillotine kills the target, or if the target dies within 0.5 seconds after use.

Cost: 100 mana
Range: 475
Cooldown: 100 / 90 / 80 seconds

Physical Damage: 200 / 300 / 400 (+0.75 per bonus attack damage)
Maximum Physical Damage: 400 / 600 / 800 (+1.5 per bonus attack damage)



Here are just a few examples of how this would change Darius for the better:

Old Darius -
"Hey Darius, you going to build some armor pen to up your damage?"

"Lol, maybe like as a fifth item.. maybe."

New Darius -
"Hey Darius, you going to build some armor pen to up your damage?"

"Will I ever! Have you seen the synergy my passive ArP has with Last Whisper!? And it will help me get kills with my ult so I can refresh the CD more often! This is so fun!"

Old Darius -
"Man, their Darius really snowballed hard; we should have our AD carries counter build against that damage."

"So... you want me to build a Warmog's or Frozen Mallet?"

New Darius -
"Man, their Darius really snowballed hard; we should have our AD carries counter build against that damage."

"I would probably do well with a quick Warden's Mail into a Randuin's late game, or maybe a Frozen Heart to slow down those passive applications. I'm glad I picked up this Wriggle's for laning, that early armor does help; and I can always swap out my AS boots for Ninja Tabi for an extra boost without losing too much damage potential."



The benefits are endless!

EDIT: I understand the need to downvote stuff you don't like; but if you guys get this thread closed you'll be cutting off discussion that at least Certainlyt is monitoring for feedback.

Be a little more responsible with your impulses, please.

That's a pretty good idea.

Everyone thinks his ulti is a problem, i personally think it's his passive what is really over the top, specially since it triggers on Decimate, which has a HUGE range

Extremely effective harrass tool > Effective Denying > Getting Advantage > Snowball

i'll probably get downvoted into oblivion by people that thinks the problem is his ulti ~ but still, it's worth it to add a diferent opinion to the thread

whatever

The problem is that you can easily see when your ult will kill when you deal true dmg. With that no-cooldown-on-kill thing, I think it's a little bit too powerful

We made Darius's ult true damage for a two primary reasons:
First, we wanted the Darius player to have some certainty over whether his ultimate would land a killing blow. Physical damage mitigation varies widely across champions and builds. It was extremely "mathy" to have to calculate what health was needed to score a kill.

Second, we wanted to make sure Darius's ult did not kill squishy ranged ADs and mages from full with low bleed stacks. When the ult was physical, the damage had to be so high to make it feel good against, say Renekton, that it was abusive versus Caitlyn. Notice that in the example you gave, Darius's lvl 3 Noxian Guillotine at max stacks with 60 bonus AD would be doing something like 300 physical damage to a lvl 18 Renekton with a Randuins and an Aegis.