Pros? At best, sexual dreams or similar. At worst, if the scare-tactic claims are true, it will supposedly suck out your life force and leave you dead.
You say you're new. Perhaps some time studying what magic is, how it works, and learning some specific tradition of working with spirits, at least, would benefit you before attempting to call on something you clearly know nothing about.
hmm when you summon something of course you taking the spirit time & energy ,to manifest to your place or project to your place , of course the spirit always have something to do , nah because you taking their time you should give a thing in return but its only a little amount of your energies ,but if you help their work ,example:doing energy work to freed the spirit from bad bindings , instead to take energies ,they will help you
remember only a little amount ,or giving treat/offering for something in return
case 1 :actually many person do bad like forcing the spirit against it will ,hurt them
exorcist innocent spirit(spirit do feel sick when exorcised from their habitats)(trees,stone,haunted building) , then of course the spirit will become angry ,dont underestimate them ,in very bad case traffic accident or death ,even family
case 2: also there is a case which the summoners is newbie ,then what is summoned is not the wanted spirit , because you open gate to other plane , so if there is something bad happening dont just blame what you call , maybe there is something following it
case 3: even though the race of spirits is same the characteristic may different , its just like human,(if you ever read story about person live with many succubus or incubus ,they simply give it names and different character& wants) so it come also with good & bad according to the spirit , not according from you
case 4: sexual spirit are often monogamous , which means if you have human boyfriend , they will not agree , often its posess the human if you cannot see them directly , then this is very bad case for other human same case with succubus
there are some case in physic vampirism , but i dont agree if there is somebody said succu&inccu sucking life into death ,like in films or that fiction
suggestion: so mind this all things before you summon something
like quija board is not for playing in children ,because the spirit will keep following
