I would like to share this video with you. It may help you with killing Crota with 2 swords only without using a titan bubble.
https://www.youtube.com/watch?v=EuW8emTu1no
English
#Destiny
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As a 34 it's so easy now. For anyone having trouble don't attempt four hits its unnecessary. One slash and three slams is enough to down him on the third kneel. It's far easier to pull off too, slash as he's kneeling then start slamming. Plenty of time to run away or drop the sword and go invisible. Make sure you push forwards on the left stick the whole time too.