Flamvell

The Flamvells are a series of FIRE Attribute monsters whose effects include burning away the opponent's Life Points and increasing each others attack points. Many of their effects are triggered when they inflict Battle Damage. They are introduced in Duel Terminal with further support in Duel Terminal - Invasion of Worms!! They are introduced to the TCG through the Booster Pack Ancient Prophecy, with Flamvell Commando as a TCG-exclusive, with further cards coming through the Booster Pack Hidden Arsenal. Aside from being FIRE monsters, the majority of them have 200 DEF, and have support based around that.

A new sub-Archetype called the Neoflamvell will be released in the upcoming Duel Terminal - Pulse of the Trishula, hinting that the "Flamvell" may be making a comeback like fellow Duel Terminal Archetype; the X-Sabers/XX-Sabers. The Neoflamvell monsters however are more focused on Graveyard control, especially by removing from play your opponent's cards.

Playability
Many of these monsters have 200 DEF, making them searchable through the effect of "Flamvell Paun". However, cards like "Book of Moon", "Mormolith" and "Ojama Country" can take advantage of this, easily eliminating these cards.

A Deck using the "Flamvell" archetype will essentially be using FIRE cards, most of which have 200 DEF or less. In this case, a Deck using these monsters will be able to utilize a great amount of FIRE support, like the "Volcanic" series. However, since the total amount of "Flamvell" monsters currently released in the TCG is 6, then to make a Deck out of it, there must be a great amount of unrelated FIRE cards. On the other hand, it is far easier to just use the current "Flamvell" monsters as support cards in other decks.