Regeneration Charge +2
Dragonborn Knights are currently one of the most powerful units in the game. They are all around hard to kill, between the sidewind, the regeneration, the high health, and the fact that you get 2 of them. The best way to kill them is: carefully. They gain 2 attack power if they move 2 or more squares before attacking, excluding sidewind, so if they get the first strike, they can be devestating. A trapped Dragonborn Knight can still be taken out with relative ease, so be caeful when using them that you don't fall into any traps.
Dragonborn Knights, despite being the 3rd unit to have the regeneration ability, are the first unit to have it set to a positive value.