Camilla, Bewitching Beauty can be a very fun, and effective, character to use if built properly. One thing in common with the first two below-listed builds: they are all quite expensive and will require skills that are uncommon. In addition, in order to make full use of these builds Camilla will need to be run on a Flier Emblem team. One upside to Camilla is that she is a relatively common character, so getting high merges is more doable.
Big Sister is an excellent choice for summoner support, particularly for the DC build, as it increases her bulk and raises her speed to top tier with Fortify Fliers. Her best IV boon overall is +Spd, which increases the stat to 35.
Stats at Level 40 5*
HP: 34/37/41
ATK: 26/30/33
SPD: 29/32/35
DEF: 24/28/31
RES: 28/31/34
Distant Counter Tank
Standard Brave Axe Build/Quad-hitting Build
Budget Build
Shouts out to Gamepress for some of the ideas for this post. Here is a link for their builds.