Here's our Crota 2 sword kill
From the beginning if you want to see the initial setup (Titans with Alpha Lupi FTW)
From the start of the interesting stuff
The general rule of thumb I followed for damaging him was,
First shieldbreak: R1-R1-R2, R1-R1-R2, R2
Second shieldbreak: R1-R1-R2, R1-R2-Super cancel (first sword round I messed this up, basically did R1-Super-R2 instead, but it worked out)
However, the most important thing is keeping an eye on his health. Assuming you have tons of time on the sword like we did, you do not want him to enrage after the third sword. You want to get him as close as possible, i.e. ~25%. It doesn't actually matter how much damage you do on the first two swords, as long as he's below 50% by the third sword you're on track to kill by enraging him during the fourth. edit: if he doesn't die, at this point you call for a third shieldbreak- MORE than enough time left on the sword as seen in this video. You want the swordbearer to die in exactly the area he did for us here.
Because you get the super on the second shield break each time, all the damage is backloaded, so you really don't have to worry about the individual amounts per break so much as getting him to the right point on the edge of enrage before your final sword attempt.
Basically, if you do all the damage possible on the first two swords, you can actually get him to the point where you'd just want to "skip" the third shieldbreak (in other words just wait, get the orbs and stay in safety until your super's up) and then finish him on the "fourth" without every having done a third (so three shield breaks
total). Otherwise, you may need to do just a couple of R1s, an R2, or whatever it takes on the third shield break- in this case I had a fair bit of damage to go so I went for basically the full combo.
EDIT: That first part of Nexus strike is perfect for aggressive Shotgun use.
Absolutely, full rooms of juicy targets...
Damn, but not so great at Sekrion.
ahahah seriously that was a bit of a handicap. shame, forgot about that detonation move XD
