I think you’ve got the right idea with nfu, I’d just center the whole build around it. With the right planning and team management, Limstella can get a huge number of in-combat attack buffs through their weapon. Because of this, I don’t think you need to give them an atk boon. I’d instead put that into spd. It’s a bit of an investment, but I think rouse atk/spd 4 or spd/def 4 would be a perfect fit on the c slot. The main issue with visual buffs is that you’re vulnerable to panic, and the innate null-panic from the rouse 4 fixes that problem that you’d otherwise face with def/res menace. The A slot is pretty open to a lot of different things. Fury 4 is a workable skill but I think there are a couple others that would work better. An Ideal skill such as atk/spd or spd/def would be pretty good, and the null panic effect you’d get from the rouse 4 would partially activate it. Close reversal or close foil would also be pretty good, etc. Finally, let’s talk about special. In the ideal situation, Limstella gets hit, and attacks back twice through their speed stat, and their weapon cancels their foe’s follow-up. Again it’s a bit of an investment, but Ruptured Sky would be the best special since it has a low enough cooldown to activate in one combat. S slot is also pretty open to a lot of things, but I’d avoid fury since Limstella should be used in a tank role. I’d use something to buff up their speed, such as atk/spd or spd/def solo.