Fixes nymph blood sucking (#8236)

code/modules/mob/living/carbon/alien/diona/diona_powers.dm

@@ -173,17 +173,18 @@
 	//For fun factor, we'll allow the nymph to choose nonvalid targets
 	var/list/choices = list()
 	for(var/mob/living/L in view(1, src))
-		if(!Adjacent(L) || L == src)
+		if(L == src)
 			continue
-		if(is_diona(L))
+		if(!Adjacent(L))
+			continue
+		if(L.is_diona())
 			continue
 		choices += L
 
-	if(!choices.len)
+	if(!length(choices))
 		to_chat(src, span("warning", "There are no life forms nearby to sample!"))
 		return
-
-	if(choices.len)
+	else
 		choices += "Cancel"
 
 	var/mob/living/donor = input(src, "Who do you wish to sample?") in null|choices