After Mahabharatha war, to avenge the death of his father Drona, Aswathama entered camp of Pandavas and killed Upapandavas and sleeping soldiers. According to Mahabhartha, Krishna curses Aswathama to roam the earth with all diseases for 3000 years.
As regards thyself, all wise men know thee for a coward and a sinful wretch! Always engaged in sinful acts, thou art the slayer of children. For this reason, thou must have to bear the fruit of these thy sins. For 3,000 years thou shalt wander over this earth, without a companion and without being able to talk with anyone. Alone and without anybody by thy side, thou shalt wander through diverse countries, O wretch, thou shalt have no place in the midst of men. The stench of pus and blood shall emanate from thee, and inaccessible forests and dreary moors shall be thy abode! Thou shalt wander over the Earth, O thou of sinful soul, with the weight of all diseases on thee.
Aswathama is destined to become next Vyasa (for 29th Mahayuga of this (Vaivaswara) Manvantara).
In the next Dwápara, Drauńi (the son of Drońa) will be the Vyása, when my son, the Muni Krishńa Dwaipáyana, who is the actual Vyása, shall cease to be (in that character).
He is also destined to become Saptarishi of Savarni Manvantara, which is upcoming Manvantara.
O Royal sage, I am now describing Sävarni Manvantara. In this particular Manvantara, Asvatthämä, garadvän, Kausika, Gälava, Satänanda, Kasyapa and Räma (Parasuräma) are the seven Rsis.
As above two events are predestined, Aswathama must be relieved from sin of killing Upapandavas and curse of Krishna.
Did Aswatthama get rid of the sin of killing Upapandvas and curse of Krishna? If so. how did he do that?