Titans: fist of panic for large enemies/ generates many of orbs. Bubble, weapons/blessing of light. Not to mention its great for when your about to die. Warlock: self rez for those very intense moments. They have that ability which gives nearby teammates a cool down. Nova bomb for those large crouds and generating a lot of orbs. Hunter: able to go invisible and revive (very useful at times) golden gun for orbs. (great with achlyophage) ark blade is good for clearing out large amounts of mobs such as thrall. So all classes are all useful in many ways for different situations dont shame on different classes because together we are a perfect team.