1- Rankings are an easy way to keep track of power levels on the site. However, it is possible to have higher stats than someone of a higher rank if one grinds enough.
2- The base stats of each Ranking are listed below:
E Rank- 25 stats
D Rank- 60 stats
C Rank- 95 stats
B Rank- 135 stats
A Rank- 175 stats
S Rank- 230 stats+
3- In order to rank up, you need to defeat an RPC of a higher rank than you in combat or complete a special mission handed out by Province leaders, which vary from location.
4- When ranking up, you automatically get 15 stats to distribute. Go nuts.
5- Each Ranking can use unlimited skills and abilities of the same rank, plus an additional one the next up ranking. This does not apply to A Rank or S Rank skills, of which only 7 and 4 can be learned respectively.
Any and all questions about Ranking Up can be asked here.