If Brotherhood of the Fire Fist - Leopard was Normal or Special Summoned this turn, it allows you to Tribute a “Fire Fist” monster to then Set 1 “Fire Formation” Spell/Trap Card directly from your Deck.
You can Normal Summon Leopard, Tribute it via its own effect to Set a Fire Formation - Tensu from your Deck, activate it and then Summon Brotherhood of the Fire Fist - Spirit, your Level 3 Tuner, from your hand. Brotherhood of the Fire Fist - Spirit will allow you to Special Summon Leopard from the Graveyard, giving you access to Brotherhood of the Fire Fist - Horse Prince, a Level 6 Synchro.
If you control another Level 3 monster, you can Special Summon Psychic Tracker from your hand. Normal Summon Flare Resonator or Brotherhood of the Fire Fist - Spirit, Special Summon Psychic Tracker via its own effect and then Special Summon a Level 6 Synchro from your Extra Deck.
If you Summon Brotherhood of the Fire Fist - Horse Prince using Flare Resonator and Psychic Tracker, they will increase its ATK by 300 and 900 respectively, making it a 3100 ATK monster.
When it’s Synchro Summoned, Horse Prince allows you to Special Summon a Level 3 FIRE monster from your Deck. If you Special Summon Brotherhood of the Fire Fist - Rooster via Horse Prince’s effect, it will allow you to add a “Fire Fist” monster from your Deck to your hand, which you can then use to activate Fire Formation - Yoko.
Once per turn, Brotherhood of the Fire Fist - Rooster allows you to send a face-up “Fire Formation” Spell/Trap Card you control to the Graveyard to Set a “Fire Formation” Spell/Trap Card directly from your Deck. You can send a Fire Formation - Yoko or a Fire Formation - Tensu to the Graveyard to Set a Fire Formation - Gyokkou or a Fire Formation - Tenken from your Deck.
Sealed Tombs Until the end of the opponent's next turn, neither player can banish cards from the Graveyard or Special Summon monsters from the Graveyard. This skill can only be used once per Duel.
Consistency can be a bit of an issue since quite a few cards in the Deck don’t interact with each other.
It’s quite easy to prevent you from Synchro Summoning: all your opponent needs is a Paleozoic Canadia or a Floodgate Trap Hole to flip your Flare Resonator or Brotherhood of the Fire Fist - Spirit face-down. Fire Formation - Gyokkou can be used to prevent this from happening, but you are not always going to have one available.