Ner'zhul, the Lich King

Ner'zhul the Lich King is an enchantment unless targeted by Frostmourne.
Now we ar one! - If Ner'zhul would be destroyed by arthas, merge as Athas The Lich King instead.
Every time a creature is put into graveyard create a 1/1 Ghoul token.
{t}{u}{u}, Sacrifice a creature: draw two cards.