parenthesis makes all the difference, found as bugreport:4631

git-svn-id: https://svn.code.sf.net/p/rathena/svn/trunk@15142 54d463be-8e91-2dee-dedb-b68131a5f0ec

src/map/skill.c

@@ -8528,7 +8528,7 @@ struct skill_unit_group* skill_unitsetting (struct block_list *src, short skilli
 		}
 		break;
 	case BA_ASSASSINCROSS:
-		val1 = 100+10*skilllv+status->agi; // ASPD increase
+		val1 = 100+(10*skilllv)+status->agi; // ASPD increase
 		if(sd)
 			val1 += 5*pc_checkskill(sd,BA_MUSICALLESSON);
 		break;