Awesome! But yes, that definitely makes sense he may be otherwise preoccupied with Irenia during that time

AND honestly any magic will work - it's more about pouring that magic energy/power into the seals to strengthen and hold back Hell itself. Because of Wrath's connection to Hell really any type of magic can work towards that if he's around. Though that does provide a cool visual of melting and resealing, or even just if Wrathion used earth magic to fill in the seals. Sky's the limit, but also, good luck with Irenia.