How does Additional skill level work?

I am confused of how this work.
Please respect my post, I may be noob about this or how this works. Hopefully I wont get flamed by the "SMART" people.

Okay here's the dilemma I am encountering right now.

My BL earrings with Piercing Rupture +2 Skill doesn't seem to stack with my Archdaeva Skill level. I am aiming for +5 Piercing Rupture, So What I have done is added the skill level of my Piercing Rupture in Daeva to +3, expecting I will get +5 Piercing rupture. But no, I got +3 Piercing rupture only and it doesnt seem to stack.

Does this work this way or there's something I am missing?

 

Oh firetruck! So having this BL earring with Piercing rupture skill +2 and aiming for Piercing Rupture +5 makes the BL earring skills pointless huh? sad.

 

First of all if u aiming that +5 with just accesories I will disapoint u. Same skill does not stack and used is only on the left (main) side if I am not mistaken. So example you have on the left +2skill and same skill but +3 on the right side, skill stat is +2 due to its place. And those stats are not stacking. Max skill from accesory I encountered is +3. So using archdeava skill with skill from accesories is , sadly imposible

 

i'll just find something that I seem to find useful. Thank you for the info guys!