Within each set, there are units that acquire their combat stats in different and unique ways. Some look for level tokens such as the Tellurian Avenger while others look for something simpler such as checking to see if you're avatar is Shadow, such as the Gnoll Runner.

Oathbreaker is no different, and here is an example of a card that gets its defense in a way never done before:

[WASP SOLDIER]

Most games, level 2 quests get swept away quickly, meaning while this unit is in play, he'll likely have at least 4 defense, unless you play him on turn one. No other unit gives you 4 defense for only 2 power, making this guy ideal for defensive situations. Late game, he gets even more difficult to kill. Two of these guys at a level 6 quests equals a massive 12 defense! The soldier may turn into your defensive unit of choice over the Dwarven Sentry.