Design Pillars

Dark Omen pillars 

1. Immersive battles
   squads oriented, slow-paced with focus on tactical maneuvering and micro-management of moderate-sized troops rather than grand armies confrontation, button mashing power-ups (e.g. strength boost)
   
   
2. Tabletop rules adherence (which emphasizes medieval warfare simulation)
   combined arms, formations, flanking, line of sight, terrain advantage, troops morale, etc
   
   
3. High fantasy setting 
   mythic races, terrifying monsters, powerful sorcery and artifacts
   
   
4. "Alive" units
   Unique units, leaders' flesh-out personalities, in-depth background, special abilities, yelling/talking leader portraits. All these emotionally attach player with units and make him care about them.
   
   

It is also worth to mention entertaining narrative in Dark Omen single-player campaign as well as music and sfx which greatly helps to pass tense of battle

features prioritization example by using pillars: