User blog comment:XCaidx/Info about F&F OE/@comment-26140304-20170209095129

Upon first impression analysis, Fei & Fang serve as offensive versions of Ark's LS, in which you have to rely on BC drops to activate the 20% mitigation buff. This can be rather a bit troublesome considering most content contains BC drop resistance. Though, they're unique in which they are the first to utilize two AoE attacks in one BB/SBB and the first to utilize both status removal and negation as a Spark buffer. Izuna is a notable mention, but she only cures status ailments and does not negate them.

Now that we know her BB and SBB carry two AoE attacks, it could be possible to see some form of self-sparking capabilities. It would make sense considering Fei and Fang are in love with each other, correlating well with the lore itself.