Tried to solo simmy drg/blu, got him to 60% then Thornton logged on, got my wyvern slept, couldnt tank and died after pd wore, then maintenance kicked us off lol
On greater birds such as this you can avoid having your wyvern slept by engaging, hitting once, letting your wyvern hit and then rotating to the other side. The wyvern will stay over there and you can continue to HB and avoid lullaby.