Can someone explain some things please?
During the Kurushetra war, both Drona tells Duryodhan and Karna that a divine weapon is needed to defeat Bhim's son, Gatotkack. Both Drona and Duryodhan look to Karna as if he is the only one with a divine weapon (which Karna uses Indra's weapon for this purpose). But it is later found out (on the very same day) that Drona has a divine weapon, too. So my question is why didn't Drona mention earlier that he had a divine weapon that could stop Gatotkach? Was this a ploy to get Karna to use his weapon so that he couldn't use it against Arjun?
Another thing: When and how did Ashwathama become immortal? After the death of Dushusan, Ashwathama told Duryodhan to consider a truce with the Pandavas, but Duryodhan tell Ashwathama to not be a coward because "Death cannot touch you. You are immortal..." So if this is the case, why would Drona believe the rumor that his son was dead on the previous day?