What follows is just a first attempt. I may come back in and revise or do a follow-up entry once I have had more time to think about it. The material below doesn't capture the film perfectly as something like Toad's invincibility would be pretty game breaking (there are ways to do it, and I may post some of the ones I was playing around with if they end up working well).
These are essentially guidelines for helping you select signature abilities to make the character in question. You don't have to take all the recommended Signature Abilities as you level, and if you want you can take other SAs instead (there are others in the book that might also fit).
It can also be helpful to elaborate on existing techniques (and to borrow ones from Ogre Gate). For instance I think Graceful Retreat would be a good WHOOG techniques to use in RBRB as the Snake's counter. Horizontal Sidestep would be a good one for Lizard. You can find all the Kung Fu Techniques in Ogre Gate on the Bedrock App on our Bedrock Games website. They have to be adapted to the RBRB system, and fit to the broader concept (though counters can pretty much be pulled right in with minimal adjustment).
I created two new Signature Abilities. These both need more testing as this was largely more of a rapid fire exercise I gave myself to do while rewatching the Five Deadly Venoms. The Martial Arts Melee style is a bit of a cheat as it exists in most movies like this, but there are several scenes where characters bust out into huge melees and handle multiple opponents so I wanted to make a new ability that captured it the way I saw it happening in the film (there are SAs that let you attack multiple opponents in the RBRB rulebook, as well).
CENTIPEDE
Recommended Signature Abilities: Heart Piercing Finger* [61], Yan’s Enduring Fists [59], Golden Crab Style [45], Martial Arts Melee [new]
Recommended Counters: Shadow Fist [68]
SNAKE
Recommended Signature Abilities: Crescent Moon Style [40], Crescent Moon King [new], Grip of the Yang Divinity [46],
Recommended Counters: Bending Reed Defense [63]
LIZARD
Recommended Signature Abilities: Flea on the Ceiling [44], Heart of Sun Bin [47] or Mind of Sun Bin [53],
Recommended Counters: Defense of Sun Bin [64]
TOAD
Recommended Signature Abilities: Golden Crab Style [45], Fearless Boxer Style [43], Stone Body Style [57], Martial Arts Melee [new]
Recommended Counters: Golden Armor Defense [65], Iron Armor Defense [65]
SCORPION
Recommended Signature Abilities: Mastermind [51], Jade Kicks [49], Studied Blade Style [57],
Recommended Counters: Insightful Reaction [65]
FINAL STUDENT
Recommended Signature Abilities: Martial Arts Melee [new], Mind of Sun Bin [53] or Heart of Sun Bin [47]
Recommended Counters: Defense of Sun Bin [64]
*Reflavored as Rib Breaking Palm
NEW SIGNATURE ABILITY
Crescent Moon King
Characteristics: Ranged, Armed, External
Prerequisite: Crescent Moon Style
You throw two blades at curved angles so they strike the target from two different directions. Anytime you use this style you impose a -1d10 to counter attempts. Make separate damage rolls for each attack.
Martial Arts Melee Style
Characteristics: Melee, Unarmed, Multiple Attacks
You are skilled at rushing in to face many opponents at once in a chaotic melee or brawl. Whenever you fight multiple opponents at close range you can attack up to 1 level worth of characters per your level in melee and unarmed combat (characters with no level count as half a level for purposes of calculating attacks). So a 9th level character could attack nine level 1 characters, three level 3 characters, 18 unleveled characters, etc. Always round down. It is recommended you make one attack roll and one damage roll for all opponents you attack in a given round.