Rapid Fire was enabled for this.
Parts equipped: Powerdrive
It's as simple as it seems - have him open with his Magma Shot and be lucky enough to have the attack lost enough to spend the whole duration of Powerdrive and, once he retracts the Magma Stream, let him go down (or not, depending on how much health he has remaining) and finish him off.
X's saber has a lot of usages and is one of the more unique things you can use as X, so I find it to be overall underappreciated by many people, even if I can see why (it requires getting used to if you want to make good use of it)
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