Soul shield fusing question

[Bowdon]

I'm experimenting for the first time with soul shield fusing. I have the diva set on (I have some spare too to experiment with).

 

I fused another set piece from the Bokgan(?) with the main state being block. I  think it had a stat of 22 block.

 

When I fused it it only went to 10 and said max. How come it maxes at 10? Is there a way to raise the max number?

 

Thanks.