Today I learned... With DK, you can rush Armlet. Max Dragon Blood first as usual. This in itself is a common build, but when you get to level 20, you can choose the talent that doubles the armor and HP regen from Dragon Blood. If you have an Abyssal Blade by this point (which is not that bad on him, considering a lot of enemy carries will get a BKB to avoid Dragon Tails in fights) you can leave Armlet always active, and all the HP regen you have stacked from your passive and the Abyssal itself cancels out the Armlet's degen completely. This is better than having the usual Armlet + Heart combo because the Heart's regen is shut down by enemy hero or Roshan damage. But standard HP regen won't.