Im near level cap and i can pew pew any mobs that are not boss's. most boss's no matter how hard i try i just can not kill them (near end game that is) i dont use kalio because i dont like her so maybe thats my issue. but again boss fights take a LOT of planning and skill to beat but even then its luck if you can pull it off aka you crit alot and they miss alot. snipers are very hard to pve but also very rewarding at the same time, many times have i fought a boss about 6 times to finally beat him in a VERY close match and when you win its amazing and you feel a real sense of accomplishment. just my two cents