So now that we have a new weapon type in in the form of sidearm why not give us a cross bow ? Could even have a new damage type in the form of piercing. Imagine an exotic cross bow capable of switching between damage types ? Void Bolts, Solar Bolts or Arc Bolts. Each bolt has a special bonus also Solar Explodes, Void causes a debuff maybe to movmemt speed or cause blindness like a titan grenade and arc can do damage over time. Regular crossbows can have the usual stuff on them and come in different flavors.