I was just thinking, you could make 'Unit HP' condition with EUD conditions on a unit (lots of them for every HP the unit could have, lots of triggers unfortunately sorta like this one:
| Trigger |
| Conditions: |
| ¤ Unit HP for unit whatever is 99 (assuming it has 100 HP to lose) |
| Actions: |
¤ Modify unit hp to 100%
|
¤ Subtract 1 custom
|
| ¤ Preserve Trigger |
and have custom as its HP, would make it easier to do effects that subtract HP or add HP by a specific amount instead of setting to whatever percentage.
EDIT: forgot to put preserve trigger in the trigger