Attach Mercenaries to block_list(bl)

[Easycore]

Hello rAthena,

I'm trying to attach mercenaries to bl, specifically in clif_specialeffect.

This is for a skill, I tried the following:

case SM_ENDURE:
		clif_skill_nodamage(src,bl,skill_id,skill_lv,
			sc_start(src,bl,type,100,skill_lv,skill_get_time(skill_id,skill_lv)));
		if(sd->status.mer_id != 0){
			struct mercenary_data *md;
			struct map_session_data *sd = md->master;
			clif_specialeffect(&md->bl, 244, AREA);
		}
		break;

But this generate map-crash. If someone knows about the subject, and can help me, I would greatly appreciate it.

Regards~