Err I get confused with the reinforcing thing. I know that it takes 420 3* rings to make a 15*.
So how many 3* rings will it take to make an 8*, 9*, 10*? Sorry I'm slow, haha..
Typically the most affordable with best bonuses would be 10-star.
So.... at 3 3*s = 2 4*s. Take a number of 3* rings, get as close to that number without going over and divide it by 3. Make sure you have a result w/ no decimals. Then multiply it by 2. That determines how many of the next ring that gives. So 24 3*'s / 3 = 8 x 2 = 16 4*'s.
24 3*'s = 16 4*'s = 10 5*'s = 6 6*'s = 4 7*s = 2 8*'s
You'll have 1 4*, 1 5*, and 1 7* as well.
So 24 3* rings will get you 2 8* rings.
Meaning to get the 3rd 8* ring to make 2 9*'s we'd have to get the 8*'s again. But using your leftover rings, you can work to it alittle easier.
3 3*'s = 2 4*+ 1 4* = 3 4* = 2 5* + 1 5* = 2 6* + 1 7*
Now work your way to 2 more 6*s
12 3*'s = 8 4*'s = 4 5*'s = 2 6* + 2 6* = 4 6* = 2 7* + 1 7* = 2 8*
With your other 2 8*'s, you'll have:
2 9-stars + 1 8-star + 1 6-star + 1 5-star + 2 4-stars.
And it takes a total for 39 3* rings for 9* Caracha solars. And if you continue to save left-over rings, it slightly reduces the 3*'s needed to work to 10*.
Let's try 15 3*'s to work for that 3rd 9* ring for 10*'s.
15 3*'s = 10 4*s + 2 4* leftovers = 12 4*s = 8 5*'s + 1 5* leftover = 9 5*'s = 6 6*'s = 4 7*s = 2 8*s + 1 8* leftover = 3 8*s = 2 9*s + 2 9*s = 4 9*s = 2 10*'s
So..... 39 rings for 9*s, add in 15 more 3*'s w/ the leftovers.....
It takes 54 3* ancient caracha rings to make 2 10*s with..... 1 9* and 1 7* leftover.
And for solars, that's upto 25 hunches a F6 per 3* ring. Assuming you do hunches every stage which is 1+(3xStages done after first hunch use in a row) so 1+(3x8)=25
54x25=1350 Perfect Hunches
However, with Star Fragments. You can trade 2 1*'s into 1 2* ring. And 2 2* rings into 1 3* ring.
So if you were to save 1-2* solar rings and trade em all in for 3*'s, you'd potentially save a bit on hunches.
I'm not gonna go too much into how much it costs for a set of 15* solars.
Hope this helps, my math may be sloppy.