I think we did a pretty good job so far:
0 Unranked ✔
1 Initiate ✔
2 Silver Initiate ✔
3 Gold Initiate ✔
4 Novice ✔
5 Silver Novice ✔
6 Gold Novice ✔
7 Disciple ✔
8 Silver Disciple ✔
9 Gold Disciple ✔
10 Seeker ✔
11 Silver Seeker ✔
12 Gold Seeker ✔
13 Hunter ✔
14 Silver Hunter ✔
15 Gold Hunter ✔
16 Eagle ✔
17 Silver Eagle ✔
18 Gold Eagle ✔
19 Tiger ✔
20 Silver Tiger ✔
21 Gold Tiger ✔
22 Dragon ✔
23 Silver Dragon ✔
24 Gold Dragon ✔
25 Sage ✔
26 Silver Sage ✖
27 Gold Sage ✖
28 Master ✖
29 Middle Master ✖
30 Grand Master ✖✖✖✖✖