This behavior seems similar to Geneticist's Hell Plant, which is a status that deals damage around the player every 0.3 seconds.
In status.cpp you can see in status_change_timer:
case SC_HELLS_PLANT:
tick_time = status_get_sc_interval(type);
val4 = tick - tick_time; // Remaining time
break;
In status_change_timer_sub:
case SC_HELLS_PLANT:
if( sce->val4 >= 0 ){
skill_castend_damage_id( bl, bl, GN_HELLS_PLANT_ATK, sce->val1, tick, 0 );
}
break;
Might not be the best way but maybe you could create a status that handles the healing over time following that structure, and make the skill apply the status for 4 seconds?
Alright, managed to solve it, user error as always.
In case people come across it, don't be lazy and try to copy paste and rename your .conf files into the import folder. They're meant to override settings, not the whole file.
I suspect the # comments might be unexpected (it is a .txt file after all) and so the server crashes when reading the imports.