He's a savvy, smart football player, which is important for an edge player. The top defensive ends in the country run blazing 40-yard dash times and are athletic freaks. But football IQ is important at this spot given the position's responsibility in containment, the pass rush and reading situations in space.
Danna's not an overly explosive athlete. If he was, he'd probably be preparing for the NFL draft right now. But he's great with his hands and upper body, he plays with a solid punch and he's almost always disciplined with both his pass-rush lanes and overall ability to diagnose what's happening.