Can we balance Darius to consider how impossible it is to escape an engage with current itemization?
His design is clearly meant to reward him for sticking to his target, as if reaching and staying on his target for 3 seconds is some sort of high skill play.
Except with the current itemization, he can just barrel into the lane at 500 MS and be rewarded for having skillfully right clicked you, then proceed to dumpster 80% of your health while building almost full tank.
His base damages need to be dropped to compensate for how stupid/low skill rushing Phage + Raptor Cloak is. At level 10, his raw physical damage for having stuck to you for those 3 seconds without using his ultimate is around 1400. Assuming 100 armor and his penetration, this is reduced to about 800. Add on his ultimate for an additional ~570 damage, and you're losing about 1370 health to an avoidable combo.
This is 100% of most bruisers' base health at level 10, and his only AD item is Phage. Even with a full tank build, you're going to survive with less than 20% health, and that's assuming you get away after the 3 seconds. Very few champions can do this; most will have him stuck to them for longer than 3 seconds, thanks to Phage.
His bases need to be brought way down, or he needs significantly less reward for being able to stick to his target.