So the Bestiary can be seen in battle? Then that solves the issue. Thank you.
Viewing post in [CGMZ] Scan for RPG Maker MZ comments
Yes, you will need to use a plugin that can add custom commands to the battle command window to add the encyclopedia, I have [CGMZ] Battle Command Window but I am sure there are others as well. The JS for the command is in the encyclopedia plugin documentation.