So it was a while ago but if I remember correctly it went somwthing like this. You need to have 3 characters, and one already has to have an exotic sword. After that each of the two other characters needs to fully upgrade the other two types of legendary swords, but do not infuse them past 280. Once upgraded transfer to the first character who already has the exotic sword and infuse past 280. That will give the questline to the first charcter and the majority of it will already be done, skipping all the kills in the crucible and farming materials! Might be a little different, you may have to upgrade them on the first character, cause I'm going off of memory so Google it to be sure.