Heroes' Hangout is the nudge I needed to explore "cast from exile" archetype. I've never played the archetype but I feel like I've been seeing payoffs here and there and want to see what that looks like. If someone plays it, I'd love to hear how it goes for you.
We've been getting a ton of playable impulse draw spells which work nicely with spell velocity themes, but more generally allow Red decks to smooth their draws and reduce variance. There are a ton of variation on impulse draws, from overpowered monkeys and powerful sagas to repeatable enchantments.
More broadly though, there are so many mechanics that use the exile zone.
Enablers
Warp/Suspend/Adventures/Foretell/Plot





These mechanics allow you to send a card to exile and cast it on a later turn. These mechanics also have a lot of good cards spread across most colors meaning you can load up on them and trigger your payoffs with ease.
Discard matters
The discard theme is conducive to casting from exile. Madness exiles before casting and so do some of the discard payoffs.





Cascade/Discover


Get a cast from exile trigger on some fun classics and the new twist on an old mechanic.
Hideaway


This mechanic doesn't have many options to chose from, but some of them are very sweet.
Junk tokens


More discard tie-ins, for this uniquely UB mechanic.
Random effects





Payoffs
Now that we have a lot of ways to cast from exile, why do we actually care?
Exile value





Some cards shine when exiled or at least give you additional value. Some of these allow you to combo with Food Chain if that's your jam.
Standouts
Here are a few payoffs that I like, mostly because they are cheap and do cool things!

Discard enabler, a bit of card selection and some potential ramp. The party lizard seems like a solid piece to the archetype since it is both payoff and enabler. You can even tap itself to pay the Convoke for a Galvanic Blast or go big and cast a cheaper Elemental Eruption.

Making evasive artifact tokens is super strong for 2 mana. You clearly need a density of exile effects, but White has a lot of cheap Adventures and Red a lot of impulse draw.
Dark-Dweller Oracle, Breya's Apprentice and Rob the Archives type cards could tie into a sacrifice theme, and Haliya, Guided by Light and Westfeldt Ardent could be more tokeny. If you are into a Heroic theme, the Adventure cards will slot in nicely there or maybe you have Stridehangar Automaton to use the artifact tokens. All this gives Pia a surprising amount of playability.

Another self-contained card. Decent body for 3 mana and promises to flood the board if left unchecked.

Another enabler and payoff. The base body + stats are already good, getting additional value is gravy.
Cast from anywhere but hand
We have another UB mechanic in Paradox, with some fun designs




There are some non-keyworded versions of the effect






What is nice about these, is that they trigger with Mayhem, Flashback, Escape, Jump-Start, Retrace, Disturb and so on. The Lost and the Damned and Spirder-Man also work with Crucible effects, making them quite potent Temur cards.
Cost reduction


These two are self-contained engines and payoffs. A little expensive for my tastes, but having the option to cast them on the cheap is appealing.
Random payoffs





Whew! The theme is a lot more fleshed out than I thought, at all power levels too! I didn't even include all of the payoffs or enablers, not by a long shot.
For my part, I'm going to try and see if I can fit a Red based archetype in my cube based around these payoffs
Party Thrasher
Pia Nalaar, Consul of Revival
Faldorn, Dread Wolf Herald
While leaning heavily on discard matters, a theme I already support and impulse drawing.
We've been getting a ton of playable impulse draw spells which work nicely with spell velocity themes, but more generally allow Red decks to smooth their draws and reduce variance. There are a ton of variation on impulse draws, from overpowered monkeys and powerful sagas to repeatable enchantments.
More broadly though, there are so many mechanics that use the exile zone.
Enablers
Warp/Suspend/Adventures/Foretell/Plot
These mechanics allow you to send a card to exile and cast it on a later turn. These mechanics also have a lot of good cards spread across most colors meaning you can load up on them and trigger your payoffs with ease.
Discard matters
The discard theme is conducive to casting from exile. Madness exiles before casting and so do some of the discard payoffs.
Cascade/Discover
Get a cast from exile trigger on some fun classics and the new twist on an old mechanic.
Hideaway
This mechanic doesn't have many options to chose from, but some of them are very sweet.
Junk tokens
More discard tie-ins, for this uniquely UB mechanic.
Random effects
Payoffs
Now that we have a lot of ways to cast from exile, why do we actually care?
Exile value
Some cards shine when exiled or at least give you additional value. Some of these allow you to combo with Food Chain if that's your jam.
Standouts
Here are a few payoffs that I like, mostly because they are cheap and do cool things!
Discard enabler, a bit of card selection and some potential ramp. The party lizard seems like a solid piece to the archetype since it is both payoff and enabler. You can even tap itself to pay the Convoke for a Galvanic Blast or go big and cast a cheaper Elemental Eruption.
Making evasive artifact tokens is super strong for 2 mana. You clearly need a density of exile effects, but White has a lot of cheap Adventures and Red a lot of impulse draw.
Dark-Dweller Oracle, Breya's Apprentice and Rob the Archives type cards could tie into a sacrifice theme, and Haliya, Guided by Light and Westfeldt Ardent could be more tokeny. If you are into a Heroic theme, the Adventure cards will slot in nicely there or maybe you have Stridehangar Automaton to use the artifact tokens. All this gives Pia a surprising amount of playability.
Another self-contained card. Decent body for 3 mana and promises to flood the board if left unchecked.
Another enabler and payoff. The base body + stats are already good, getting additional value is gravy.
Cast from anywhere but hand
We have another UB mechanic in Paradox, with some fun designs
There are some non-keyworded versions of the effect
What is nice about these, is that they trigger with Mayhem, Flashback, Escape, Jump-Start, Retrace, Disturb and so on. The Lost and the Damned and Spirder-Man also work with Crucible effects, making them quite potent Temur cards.
Cost reduction
These two are self-contained engines and payoffs. A little expensive for my tastes, but having the option to cast them on the cheap is appealing.
Random payoffs
Whew! The theme is a lot more fleshed out than I thought, at all power levels too! I didn't even include all of the payoffs or enablers, not by a long shot.
For my part, I'm going to try and see if I can fit a Red based archetype in my cube based around these payoffs
Party Thrasher
Pia Nalaar, Consul of Revival
Faldorn, Dread Wolf Herald
While leaning heavily on discard matters, a theme I already support and impulse drawing.