threatening presence is a skill our voidwalkers, voidlords, felguards and wrathguards have. it's a cool skill. it's like a paladin's righteous fury, but even stronger.
http://www.wowhead.com/spell=112042
take a good look. mod 1000
there's a problem about it though. it makes tanks angry. and angry tanks ask people to vote kick you and call you names. they are mean. you don't want to attract that kind of attention for yourself, do you?
another problem: the skill is kind of hidden. your pet bar only has 4 buttons for skills and your felguard has 5 skills, so blizzard chose threatening presence to stay of of the bar. not their smartest decision ever lol
so choose one of your felguard's skills, take it off his action bar, put threatening presence there and turn it off every time you get into a group where you aren't the tank
(I chose felstorm, because I can trigger it with command demon, so why keep it there? lol)