This synchro monster has the ability to equip Magistus monsters from the extra deck to itself, and when it does, the opponent cannot summon monsters from the extra deck that are the same card type as the equipped monster
apply that monster's effect that discards itself to activate, then place that monster on the top or bottom of your Deck
Still, after using its effect, Volcasaurus can be used as material to summon other monsters which can attack
This helps to ensure that you have creatures to cast at every turn of the game
They reward you for casting spells or controlling permanents that you don't own
Im sad we didnt see any new battles, as this seemed like the most obvious set for them, but I understand the timing wasnt on their side for including them