Also, cut Sheltering Ward to mainboard some Golgari Charm, they function sort of the same, except sheltering ward doesn't protect your guy against sweepers.
My main qualm with what you are trying to do is that traditional Frites decks have a potential 8 reanimation spells (virtually, yes) while you have only access to 4 without the use of the 2 Transguild Promenade in your deck. I think that trading a forest or two and a mountain or two for Overgrown Tomb and Blood Crypt doesn't hurt you as much as it helps you. I would also like to see black for the access to Grisly Salvage and Jarad's Orders (and for that matter the extra value from Lingering Souls). I wouldn't listen to the hate about Gisela just dying either. If you're running a similar early creature structure to what you're running, removal will get used on them. Every creature dies to removal. I think Ring of Valkas is a weak card overall. Ditto for that whole cycle of equipment. It's eating four slots in your current build uselessly IMO.
See, I like accidental "Oops, I won" combos that the opponent never anticipated and isn't necessarily the game plan for winning. That is only really a thing in the standard environment though, where the need to combo out isn't as pressing.
My current Golgari Zombies deck has a two card "combo" with Ghoultree and Jarad, which can be really unfair. Especially when combined with Rancor.
But, back to faith's reward I don't think there is anything that you can do that is remotely combo-ish with it. More synergy.
I can think of a RWB list that I wouldn't mind running that could be pretty saucy. But the card choices in this particular list lend themselves better to Junk colors.
Thing is, if you want a token deck, Lingering Souls and Sorin are too good to not play for what you're trying to do.
As appealing as these combo ideas sound, it seems to me that the lack of success so far boils down to the mana requirement. I'm not particularly knowledgeable about the history of magic combos, but I can't think of a single combo that requires more than 3 or 4 mana at one time to go off. Swans only used a 3cc creature and a 2cc enchantment; Living End cycles a bunch of fattie for one mana each, and then easily finds its win cond by cascading off a 3cc spell; Thopter-Sword only used two 2cc artifacts; Dark Depths only used a specific land and a 2cc creature; Second Sunrise, a.k.a. Eggs, requires a lot of cards, but none cost more than 3cc, and all your "eggs" cycled without any net mana loss.
I'm not trying to be a killjoy here, just a realist, so if there's a mana-heavy combo I'm not thinking of, I would very much like to know it, as I think it would help to see how you can overcome this mana-restrictiveness that seems to limit the effectiveness of combos.
Dragonstorm combo required at least 8 mana to be cast. A lot of combos require an ass ton of mana. It's just that it a combo, when it goes off, should be causing you to win before the opponent can say anything about it. (Dragonstorm used a lot of ritual spells and such to hit the high storm count, but you see my point I'm sure.)
As far as setting up that synergy, I wouldn't waste your time. It costs 8 mana to do. If you're playing enough creatures for it to be worth it you should have probably won by now.
I think bonfire is bad based on the grounds that you have a lot of chance of revealing it or drawing it from effects like Forbidden Alchemy or Desperate Ravings. It is generally just a bad sweeper when you can't miracle it. I think you don't need it when you consider Supreme Verdict and Terminus are already in the deck. Terminus is weaker in this deck because it is improbable that it will be cast at miracle cost, but at 6 Terminus is still strong. 6 mana would get you little better than a pyroclasm in this build.
Delver still seems ill-placed in this format, especially with the latest GP being such a strong showing of aggro and tokens. It seems to me that your land count is a little on the low side, but you have some draw and a very low top end, but you might have some trouble doing real work with Snapcaster Mage. Might be just me, but I see Essence Scatter as being worse than Dissipate, simply because dissipate can exile and counter things that aren't protected by cavern of souls (ie noncreature spells).
I sort of like the idea you have here, but I also don't think mono-U is the way to do it. Going into white gives you access to Azorius Charm and ilk. Going into Red gets you burn and looting cards.
Also, I think it is wrong to not be running Runechanter's Pike. As a two-of. Playing it and saying oops, I win. Or, it is kinda mana intensive, but it allows you to swing with one guy, then equip it to another to hold back as a blocker.
Jace's Phantasm might also be a good one drop for you to consider. With thought scour and opponent's Grisly Salvage et al.
Advice: Don't take aggro advice from the guy who runs Volcanic Strength in his sideboard. Also, don't take advice from the guy running Furor of the Bitten, Vexing Devil, Pyreheart Wolf, and Mogg Flunkies. Definitely don't take advice from someone who wants to reliably curve out to Hellrider T4 with only 20 land in his deck two of which are Hellion Crucible. And if he says he gets it reliably, definitely shuffle his deck for him if you play against him.
Also, Counterlash seems like a fairly terrible way of doing that, considering it's only saving you three mana on Worldfire as it is, but costing you two cards (one of which must be a sorcery and also costs mana).
You'd have to run counterlash and Worldfire in your deck, and enough cheap sorcery spells and instant speed burn spells to pull it off. The Epic Experiment idea seems more solid (and even that can whiff hard).
I believe these fine people are right. The deck as it sits now is beleaguered with a good deal of mana problems.
To fix this, pick red or green as your main color, and use the other as a supporting color. I would say green for your main color, with a backup of red burn and Huntmaster/Hellkite. This means removing the ash zealot. Ash Zealot is great, but you just can't support it right now. Also, Rancor is amazing for aggro. Run it.
Also, I think four bonfire is way too much, and abundant growth is really clunky in aggro.
I like the idea of the interaction being put into a R/W control shell. Unfortunately, there isn't a whole lot of great controlling white cards without blue.
For this deck idea, I have one suggestion. Magmaquake?
Ground Seal is a good sideboard card. It turns off Deathrite Shaman, Unburial Rites, Angel of Serenity (sort of), and that ilk that plan to abuse the graveyard, but does nothing at all to your strategy of scavenging.
Also, cut Sheltering Ward to mainboard some Golgari Charm, they function sort of the same, except sheltering ward doesn't protect your guy against sweepers.
My current Golgari Zombies deck has a two card "combo" with Ghoultree and Jarad, which can be really unfair. Especially when combined with Rancor.
But, back to faith's reward I don't think there is anything that you can do that is remotely combo-ish with it. More synergy.
Thing is, if you want a token deck, Lingering Souls and Sorin are too good to not play for what you're trying to do.
Dragonstorm combo required at least 8 mana to be cast. A lot of combos require an ass ton of mana. It's just that it a combo, when it goes off, should be causing you to win before the opponent can say anything about it. (Dragonstorm used a lot of ritual spells and such to hit the high storm count, but you see my point I'm sure.)
The difference between combo and synergy:
1.) Synergy happens naturally in decks and while certain cards interact better with other cards, it isn't the only game plan.
2.) Decks are built around combos, and usually when the combo is set-up the game is over.
Example: Dragonstorm with 4 storm count searching out Bogardan Hellkites is a combo deck.
Grisly Salvage setting up a cheap Ghoultree is synergy.
As far as setting up that synergy, I wouldn't waste your time. It costs 8 mana to do. If you're playing enough creatures for it to be worth it you should have probably won by now.
I sort of like the idea you have here, but I also don't think mono-U is the way to do it. Going into white gives you access to Azorius Charm and ilk. Going into Red gets you burn and looting cards.
Also, I think it is wrong to not be running Runechanter's Pike. As a two-of. Playing it and saying oops, I win. Or, it is kinda mana intensive, but it allows you to swing with one guy, then equip it to another to hold back as a blocker.
Jace's Phantasm might also be a good one drop for you to consider. With thought scour and opponent's Grisly Salvage et al.
You'd have to run counterlash and Worldfire in your deck, and enough cheap sorcery spells and instant speed burn spells to pull it off. The Epic Experiment idea seems more solid (and even that can whiff hard).
To fix this, pick red or green as your main color, and use the other as a supporting color. I would say green for your main color, with a backup of red burn and Huntmaster/Hellkite. This means removing the ash zealot. Ash Zealot is great, but you just can't support it right now. Also, Rancor is amazing for aggro. Run it.
Also, I think four bonfire is way too much, and abundant growth is really clunky in aggro.
For this deck idea, I have one suggestion. Magmaquake?