What kind of sin is using adult sex toys and what will be punishment in afterlife for that? Is it same as fornication?
Mentioned that for someone who does masturbating, would it be more punishment for using toys?
Well simply said:
There are 2 possible situation that come to mind:
The fatwa (in Arabic) #257782 on islamweb for example says that using a sex doll for instance is haram (evidence see the verses I'll quote later and it's interpretation) while they hold the opinion that masturbation is allowed in extreme cases to prevent zina.
And they who guard their private parts
Except from their wives or those their right hands possess, for indeed, they will not be blamed -
But whoever seeks beyond that, then those are the transgressors -
so this was considered as seeking pleasure beyond the allowed and not guarding their private parts and seeking "foreign" pleasure. However I know of a fatwa from a scholar even allowing this based on the same arguments which are used by those allowing masturbation!
While the use of sex toys in general and role playing (games) for spouses is allowed as far as there's no transgression -as described- and it is a conjugal matter.
So far the legal status:
Note that a punishment can only be applied for something where the Shari'a has prescribed a punishment, on the whole the only sinful act here can be considered as masturbation or equal/analog to masturbation and even if masturbation is considered as a sin by the majority of scholars none of them say it is punishable!
So what ever sinful you do in this matter or commit you must only repent it is still a sin even if it wouldn't take you to a shari'a court unless you've done it in public...