Future Pain not counting multiple casts / dc bug

[SkagHunter]

When casting future pain, the 4th level divination spell, if you hit a target with it multiple times before they 'hit' the target will only have the spell affect them once.
Unsure if intentional or bug.
There was also a bug with the DC at one point, it showing up roughly 7 points below what it should be

[SkagHunter]

Additionally, casting this on a blue henchman / summon in the open door will result in area wide faction bug when it fires off.