ahh ok, i manage to get senior alchemy

from what i tried few times.

demon gloves + copper crest + sea armor

result :

steel thorn bracers x1
common stone x1

net iron boot + dino tooth

result :

skeleton iron sword x4
common stone x1

skeleton iron sword + vertical wing

result :

delicate wood x1
wooden gavel x1

from these alone i can pull a conclusion that....

its the same with junior alch which the result of compound follows the highest rank (same as junior) the common stone result bothers me tho...it felt i left out something @_@

but then again, i've only tried a few compounding..i might be mistaken about something~