I require a little help on my build

First off, Dragon Fang really is not too good of a special; takes too long to charge and doesn't help sustain like Aether does- take your pick from Moonbow, Glimmer, Luna or maybe even Aether, all would work wonders here. You could run Desperation instead of Wrath as you would hit so hard and so fast with Brazen active and hitting twice in a row would cause Blucina here to wreak havoc. And finally, most importantly, get rid of that Quick Riposte 3 seal- 39 speed is amazing, and that Quick Riposte can be made better use of by many other strong but slower units. In its place, Heavy Blade+Brazen+Desperation+Glimmer can be an extremely devastating combo, as you can proc all these effects at once when initiating below 75% HP, and utterly pulverize your opponent with an instant guaranteed two-hit special. Otherwise, you can just run another Drive skill as her Seal to help her continue her amazing role as a support unit.

Your Lucina appears to have an offensive, not supportive build, so along with that Glimmer+Brazen+Desperation+Heavy Blade op combo, her best ivs are, in my opinion, -HP+Atk, as -HP helps her enter that sweet <75% HP range all the more easily, and her Speed is already really good and the more Attack, the better for the build she's running.