The description of the Gloves of Soul Catching state, in part (Candlekeep Mysteries, p. 169; emphasis mine):
After making a successful unarmed strike while wearing these gloves, you can use the gloves to deal an extra 2d10 force damage to the target, and you regain a number of hit points equal to the force damage dealt. [...]
Based on this wording, I have 2 interpretations on the number of hit points you regain from this ability:
- Only the damage from this item: You regain an amount of HP equal to the 2d10 force damage dealt by this particular item.
- All force damage dealt for this attack: You regain health based on the total amount of force damage dealt as part of the same attack (the sum of 2d10 force damage dealt by this particular item plus any other force damage that was combined with this attack).
An example of the latter would be the Way of the Astral Self monk, where their attacks dealt using the Arms of the Astral Self feature would also do force damage. Does the amount healed by the gloves include this damage along with the 2d10 extra force damage dealt due to the item?