Help with Pyra Magna/Megaempress's axe

I finally received the other day my Megatronia set.
While I was building the sword, I noticed two pegs on Megaempress's axe, and I got no idea for what they're for.
I thought they were for a weapon storage in robot mode (like Lunaclub's and Moonheart's swords on their hips) but I can't find any peg on Megaempress compatible with the pegs, and the instructions say nothing about them.
Is it something present in Victiorion's instructions?
While I was building the sword, I noticed two pegs on Megaempress's axe, and I got no idea for what they're for.
I thought they were for a weapon storage in robot mode (like Lunaclub's and Moonheart's swords on their hips) but I can't find any peg on Megaempress compatible with the pegs, and the instructions say nothing about them.
Is it something present in Victiorion's instructions?