Scrolls of Enthunder II can be purchased from Macchi Gazlitah in Ru'Lude Gardens once achieving rank 3 with her shop. In addition, Hover Tanks in Temple of Uggalepih have a chance of dropping its scroll.
Enthunder II is the first of the second tier En-spells for Red Mages to learn. When used, Enthunder II grants the Enthunder status to the caster's attacks, dealing an extra attack with the user's auto-attacks, while also increasing the user's lightning-elemental damage potency and reduces the target's resistance to the earth-element with each successful attack with the status on. With these effects in mind, Red Mages should often rotate Thunder and Stone spells in conjunction with their auto-attacks.