Make Syphon Strike deal damage with increased MP returned in PVP, with that increase dealt as damage to the target's MP. Letting them attack a healer and decrease enemy dmg output would extend the encounters, bleeding the enemy healer's MP at an increased rate. I do this on SMN, repeat bane and using virus to nerf enemy burst with the focus to extend the fights and bleed the enemy healer of MP. A DRK/SMN team would noticeably bleed a healer more quickly, nerfing burst dmg, and generate more wins for these two jobs that are lacking in their own respective roles. It would be another synergistic combo to add to the scary WHM/BLM teams.

But people would cry OP instantly because heals would be disrupted.