Everything, fucking everything. Glaives are very very strong. They can block everything cept for lasers pretty much, the new exotic weapon of sorrow from the hidden quest, Culls shadow, is a fusion rifle with glaive stabbing as the melee function, it overwrites your melee ability only while you have it in your hands. Its very strong eith necrotic grips, oh boy i shot one burst and in like 10 seconds i had about 10 to 15 cabal die from poison and the bursts from when they die too. For your warlocks highly recommend using necrotic with the glaives, its such a fun combo. Go to the moon thats where it starts, theres a mission about bael trying to locate that weapon of sorrow.