Troll Darius build with runes and masteries that work
What you want to run is ad per level marks and quints, armor per level seals, mr per level glyphs, and 0-30-0 masteries.
All you need is to build tank items, if you are ahead like 5-0 get a brutalized then keep going tank, your base and scaling is more than enough.
Why would you run such a troll setup? The main reason is because of how well this works. Your base damage is more than enough to still fight full damage people.
Where does this build work best? Say you're level 8 and rushed a randuins and another cloth armor vs a Riven who has a lee sin jungle ganking you. You'll be so tanky and your base damage will be high enough to kill one or both of them.
Run teleport for best results.
Before you hate this build test it out.