"Molten Conduction Field" can be used to send any "Laval" and "Laval Volcano Handmaiden" to the Graveyard. The effect of "Handmaiden" can be used to send another copy of itself to the Graveyard, which in turn can be used to send a third copy to the Graveyard, which can be used to send any other "Laval" to the Graveyard, satisfying the requirement to get 5 FIRE monsters in the Graveyard with a single card.
You can also use this card well in "Jurrac", "Volcanic", and "Fire King" decks due to all of their monsters being FIRE, and the last two decks' ability to quickly fill up the Graveyard with FIRE monsters.
You can also make use of "Solidarity" if you want to make it go more offensive.
If you use this option, you can summon 1 Pyrorex one turn and use its effect, then summon a second on your next turn, and use its effect, and then during Main Phase 2 Xyz Summon "Heliopolis". This way, you can hit for at least 5600 damage and prevent skipping your Battle Phase while also not losing out on "Pyrorex's" effect.