Not sure why this idea appeals to me so much, but I dig the sagas and Rona seems like a great commander to justify synergizing around them, since she can turn them from a 1-shot value spell into a repeatable engine that generates value every turn.
So the plan is, run all 7 UB sagas, and try to make all of them as good as possible, using Rona as the glue to allow replaying the sagas over and over. Naturally, this will require a few things:
-The Sagas themselves
-tutors for the sagas
-synergy pieces for the sagas (obviously overlap and cards that don't totally suck without synergy would be ideal)
-synergy pieces for sagas and rona in general
So let's take a look at each of the sagas and try to think of ways to exploit each of them.
The Eldest Reborn - This is the easiest, and one of the hardest, to exploit. It's easy because it's always a great value proposition, and it has natural synergy with Rona since she can be reanimated during the third phase and recycle it, giving value forever and ever. But it's also hard because there's not a ton of other ways to synergize with it. The only one that really comes to mind is archdemon of depravity to make the sacrifice hurt (could also use stuff like night of souls' betrayal). Could throw in megrim-type stuff, but that seems really weak. Could throw in some big fatties to reanimate, but that seems like a lot of work when I can just reanimate rona or something spicy my opponents had.
Chainer's Torment - The first 2 phases are fine, if not particularly exciting. Could include some lifegain triggers, but that seems kind of minimal. The third phase is easily the most interesting, but also kind of the worst, since we're committing half our life just to get a big token fatty, and it's not even repeatable. In fact it keeps getting worse the more we replay it, since our life keeps getting lower each time, increasing the risk and minimizing the benefit. So the goal here seems to be to find ways to recoup the life loss, and take advantage of our big fat token. Simplest way to do both is anything that gives lifelink, especially in conjunction with something that gives haste. Equipment in general seems great, since we'll have all our mana untapped the turn we get the token. There's also ways to exploit the fat body without using it in combat, such as disciple of bolas. I'm not sure if there's anything that would prevent the damage that chainer's torment deals in our colors - if there is, I'm having a hard time finding it.
rite of belzenlok - This is probably the worst of the sagas, and it's a little tough to exploit, given that the big reward is just a 6/6 flample. But it does have some synergy with the classic grave pact strats, since it gives us bodies and a sac outlet of sorts. It also benefits to a lesser extent from the equipment that works with chainer's torment, so that's a nice bonus.
Phyrexian Scriptures - much like eldest reborn, this is a fairly high floor card that's tricky to synergize with. Besides obviously working best with artifact creatures, I think proliferate is particularly clutch here, since the delay on the board wipe phase can really hurt its usefulness, since the second phase is easily the best. The first phase obviously goes well with the second, but it's pretty low-impact and probably not worth spending a bunch of effort to synergize with directly. The third phase is also a bit less exciting - I could throw in stuff like web of inertia but that seems like a bit of a stretch.
The Mirari Conjecture - Pretty straightforward and powerful synergy with instants and sorceries. Making sure to have a sorcery to recur is easy enough, especially with the tutors and such we'll need to hit our sagas reliably, but maybe add some cantrippy instants like impulse to make sure we can hit instants on schedule. For the big third phase, we'll want to focus on instants and sorceries that are effective when cast on our turn and in mutiples, like draw, tutor, removal. In particular, stuff that can bounce/flicker creatures so we can reuse rona could be good.
release to the wind[/card]
Time of Ice - Power varies a lot on this one - versus a voltron deck that lacks hexproof, this is pretty auto-win, but there will probably be lots of decks that don't care about this, or worse, can use it to exploit them etb triggers. My main thought, then, is - if you can't beat 'em, join em. If you can tap your etb creatures on your upkeep or in response to the triggers, you can get the back to hand, and in particular Rona comes with her own tap ability, isn't that convenient (albeit expensive). The most efficient way to tap creatures that don't have tap abilities themselves is probably vehicles, so a few of the better ones of those can go in. You can also run silly stuff like blustersquall to get a bad cyc rift impression.
The Antiquities War - Most exciting for last, arguably. The first two phases are pretty straightforward - run artifacts (which is also good with rona herself). The third phase does great with token production, as well as cheap cantripping artifacts and mycosynth lattice. While the rest are mostly value-oriented, this one looks like more a finisher to me, alongside maybe chainer's.
General Saga Synergy - A few things come to mind - anything that doubles triggered abilities (so probably just strionic resonator then), anything that lets us return the saga to hand, proliferate to speed up the stages, enchantment copying to double down. mirage mirror should work, since it doesn't trigger until draw, which is a nice bonus.
Rona synergy - We could run training grounds to help out her anemic draw ability, but idk if it's worth the effort. The bigger angle for synergy is obviously the ability to reuse her trigger, so any kind of flicker or bounce is good. I'm slightly nervous about conjurer's closet, since you've got a wide window between exiling your crucial sagas and actually casting them. Also any kind of recur is going to be good. We could also run other targets to recur - artifacts, planeswalkers, other legendaries - but I'd like to generally avoid those unless they're particularly synergistic with the sagas, since I don't want them to overshadow the sagas as recur targets.
I think you are waaaaaay better off not playing Chainer's Torment and Rite of Belzenlok. I mean they are just so terrible. There is enough theme going on with the other Sagas, slotting in cards to make those better.
You need a good threshold of instants and sorcery for The Mirari Conjecture, good number of artifacts for The Antiquities War, so I'd focus more cards slots on them to make the deck more themed around them, rather than put in two Sagas for the sake of Sagas.
Entomb is an additional tutor for the Sagas with Rona.
Doom Whisperer could be a good way to get cards into your graveyard and smooth out your draws, and setup the top of your library for Rona activated ability.
I'd say now is as good as any time to try out Bolas's Citadel as Sensei's Divining Top is a certain given Ronas activated ability. It's a nice hit for The Antiquities War. The main bottleneck of Bolas's Citadel is going to be lands on top, so I like that Rona can be used to clear a land to get more chances of spells. So it doesn't have to be infinite, just real nice value.
If you do end up running Mycosynth Lattice then Karn, the Great Creator is a lock. But what's cool with Karn is that he can get artifacts cards exiled with Rona. So if Rona is killed before you got to have cast an artifact, then Karn can retrieve it, he doesn't care about "stamps".
Definitely the deck would be better if I focused around fewer synergies, but the challenge of the deck is to try to make it viable with all 7 sagas. Anyway I think they both have something to offer - chainers has a big downside, but sacking the token to disciple of bolas is pretty insane value, so it does have at least some worthwhile synergy. Rite of belzenlok isn't as exploitable, but it's got a pretty ok floor, making 5 bodies over 3 turns. It's probably the worst saga, granted, but one of them has to be.
Good call on entomb, we'll want all the tutors we can get probably.
I'll probably avoid wincons that don't involve sagas, like karn + lattice or citadel + top, as the goal is to focus around the sagas and they can probably pretty easily get outgunned by more powerful effects. I don't think karn's -2 will be particularly useful anyway, since I'll probably be casting whatever is exiled immediately, and will be hitting sagas most of the time (hopefully).
So I got to play this a bit last night. It didn't go amazingly, but a lot of that I would chalk up to a lack of interaction. Had a lot of games that ended to early explosive plays that could have been easily handled by a single counterspell or removal. Why don't I just always play Phelddagrif, anyway?
Anyway, it did actually go better than expected, and I think the biggest part of that is thanks to the universal synergies. Being able to tick up and down sagas to keep repeating the best bits was pretty cool. Probably the strongest saga was the mirari conjecture, which led to my one win. Never got to play antiquities war or time of ice, unfortunately. Although looking at the antiquities war, it seems kind of hard to really win with it, given that it's so telegraphed. Unless you get a sweet spell swindle for 6+ the turn before the final phase or something.
As a lower-powered deck I think it did an admirable job, and it was fun to use the sagas so much. But it's difficult to include answers at the same time. If I tune it up at all, I'll probably cut back on the saga-specific synergies, ramp up the generic ones a little, and put in more counters and removal. You know, like I always do.