How can I find the katryx ore and make a katryx blade ?  And where is the lost and found centre ?

for katryx ore you can look here Ores locations - Renryuu: Ascension community - itch.io 

lost and found can be found in your castle first room right side

thanks

And i can't findthe girl who open doors ，can you tell me？please！！！（i have find it twice but i forget it now！！！）

open locker doors