To be able to weaponize gravitation it would be necessary to bend the curvature of spacetime in a localized region. Instead the region where the spacetime curvature has been massively increased there would be a massive increase in time dilation. Time dilation will mean inside that localized region time will be slower compared to the time outside it.
Increasing the curvature of spacetime avoids the need for adding huge amounts of mass to a region to dilate time. This assumes there is a technique for manipulating the curvature of spacetime independently of mass.
For someone trapped in a highly time dilated bubble time outside the bubble will be passing slowly. Due to the quirks of relativity, while time inside in a region of high time dilation will appear to move slowly, time outside the time dilation bubble will appear to be passing slowly for someone inside it.
Will the enemies of the person trapped in the time dilation bubble be able to do lots of nasty things to their victim? Yes they can, but it might be difficult to do much that is useful or effective. The victim is trapped at the bottom of an immensely deep and powerful gravitational potential well. Sending anything down into it cause it to arrive at a velocity close to lightspeed. That's good for destroying someone, but not very good for tweaking their body in some naughty ways.
The amount of time dilation necessary to trap someone inside a slow time bubble will be the equivalent of the time dilation of being very, very close to a massive black hole. This is the catch: the amount of energy needed to do that will be astronomically stupendous. Probably, about the mass-energy equivalent of that massive black hole. Possibly, this might be conceptually bypassed if the curvature of spacetime can be increased as if mass was present, but the increase in curvature can be done with incredibly small amounts of energy (relatively speaking).
In conclusion, weaponizing gravitation would need to be accomplished with a form of physics unknown to current science. This can be assumed to involve techniques for increasing the curvature of spacetime and not adding remarkably huge of mass to the location of the time dilation bubble. To anyone inside the time dilation bubble will see time passing slowly outside the bubble and people outside the bubble will time passing slowly inside it. Sadly, its practicality as a weapon isn't very practical. Not unless you want to do something extremely nasty and deadly.