If we include Her Boost + Amp + a 20% Fire Increase, we get a 95% Fire Damage increase plus with Hototogisu's +10 Magic = Nuke of high levels.
Most people would say just use Amp + 50% Increase Item, but that's harder to come by (at least for me), so I just use the 20% increase item more.
I believe that with the weapon, accessory, amp, mind charge and her Burning Petals move she can put out more fire damage than the MC unless you build and grind a Surt to 99 mag. That thing hits like a steamroller, no party member can hope to even touch that kind of damage.
It can be boosted even more for some movie trips but that sucks up time.
Yukiko has that 50SP one that you can get pretty early. Not amazing by any means, but still useful.
But yeah, you should really only use weapons that have some type of bonus on them, unless you're just using the Rush command for everything.
This. She's not an attacking character really, so the more SP the better. Combine that with the Chakra Band (I may be wrong with the name) which cuts SP costs in half, that adds 2-3 more uses of Burning Pedals. Or quite a few uses of Salvation. --- PSN: LegionTheMany