Question for my 40+10 Ninian

Is this for offense or defense?
But whether it is for offense or defense, I thing wings of mercy would work nicely in term of allowing her to be more mobile, flexible, and being able to catch up to the speed of a horse emblem...
Honestly the main purpose of ninian is dance and providing buff, which this reasoning also supports the usage of wings of mercy... If it wasnt for that she has optimal IV and +10 she would never reach 43 spd, though that speed is enough for desperation...

Perhaps the argument is that if you wanted another offense character, you would use another more offensive character instead of ninian in your team.. Using ninian in your team meant that a dancer is wanted, and wing of mercy helps this dancer does her main role better, while her second role, with stats this high, is to help her team deal some extra damage or keep herself alive. Vantage works well with the latter role along with keeping herself alive, Wings of Mercy would help with her sticking to her team and support her team in case the map is very clumpsy (especially those with a mountain in the middle)

Desperation is perhaps not the most optimal in term of role imo because if you wanted a carry who can hit hard, you can just find and put in a carry in your horse emblem that can hit hard and run desperation... Unless you wanted your ninian to have prioritize damage dealing, then supporting as secondary role...
then in that case, its arguable to put in desperation as her B slot ... but honestly vantage works quiet well in this judging from her stats, weapon, and A slot