Seeing as there are alot of threads asking about how to get this lore done I decided to put together a video of me getting it done. After I realized that you only need the second kill to get the double kill it made it extremely doable and I was able to get the lore done in about 10 minutes prior to learning about it.
Basically after any point of getting a kill just activate your core discharge, rather you feel you are near an opponent or not, if you are not, just blow up some minions, if you are, go for the kill! If you feel your life is in danger you can always just cancel the ult by hitting triangle and just try again in a minute or so. Run skill damage build if possible and go for crit hits with it. Here’s the vid.