Which boss? Also, always try to get human help. It's a lot more useful than the stupid ai who will let itself get killed easily.
Psh, even the AI help - nevermind other players - can be abused so badly in Souls games if you work the boss right to change its targeting between you and the AI constantly - basically renders a boss useless. Only time I ever used summoning was in DS1 when it was necessary to unlock some particular items. In Bloodborne, you actually have to *pay* to summon others, whether AI or players, which I can't help but pompously approve of. :D Although I still think the price is too low...
the problem is that i cant find any human players to summon. im talking about that knight guy who comes out of the ground and pulls out a half buried stone sword. i tried sorceries, hexes and pyromancies on him but except for sorceries the others dont do any damage (cant use miracles, no faith).
That dose sounds like fume knight
The easiest way is to kill him is with a crossbow.
First stage is somewhat manageable but the second has so few openings it's best to kite him to death.
Can take up to 30 minutes tho.