Cassie deals an additional 8% of a target's full hp with Big Game. If Raum has his full soul armor at 8k health, she does about 1320 a weapon shot for 4 seconds. That's 5 weapon shots, which is 6600 damage total, assuming she hits all of her shots.
This one mostly depends on aim. Though Lian has a slight advantage because her weapon is hitscan, so shots travel faster. Though if Lian's misses her presence shot, Cassie wins.