The Riot Blade to Rage of Halone is a very potent combo. Maybe I am the only one that had the issue, but the only way I could get it to activate was by performing Riot Blade from behind the enemy. I kept having to Shield Bash to stun, run behind and Riot Blade, and then the Rage of Halone combo would trigger. I guess it makes sense since Riot Blade has a bonus when performed behind the enemy.