I can work with this…
Well, clearly this is meant to fuel Delve and he has an ability similar to Delve anyhow. However, at five mana, I don’t think that’s exactly what you want to do. I mean, you can’t exactly turbo out a Zombie Fish with this and you can’t even play Tasigur. I guess this was seen as too powerful at a lower casting cost (with lower P/T as well, of course). There are a few Delve cards I would like to play here, however.
The question is, is the card selection strong enough to not need card draw? Probably, although not being able to double spell ever is going to be a disadvantage. However, we can mess with drawing. Sadly not very much, but a little bit.
Admittedly, shelling out several hundred euros for Chains isn’t exactly what I want here, and there just aren’t enough of these cards to have this be an actual theme of the deck. Subtheme maybe, but let’s forget about the Chains anyhow.
What else can we do? Flashback seems good.
There’s also various creatures with Embalm or Eternalize (basically Flashback for creatures).
The problem with these two approaches is that these cards are manaintensive. They usually cost a bit more than similar cards without those abilities and quite a bit more from the graveyard.
What else can we do with our graveyard? Well, there’s over thousand cards that mention graveyard in these colors, so there’s bound to be plenty of options. Not that all of them actually work with Taigam very well or are any good otherwise, but we’ll see.
Well, that’s over 60 cards, so plenty of cuts need to be made. I want plenty of manasources here, as I don’t ever want to miss playing Taigam on curve. That means close to 50 sources. The good thing is that we can later on choose to not take the manasources and simply put them into our graveyard, if we have enough. For this reason, I would like to keep the curve fairly low, although we can also always simply put the expensive spells into our graveyard as well.
I’ll leave certain cards in the deck I otherwise wouldn’t play in EDH. Again, if they are too situational and that situation hasn’t come up, we can just put them into the graveyard. There’s so many interesting ideas here, that I don’t actually know what to cut. I’ll cut [scryfall]Mortal Combat[/scryfall], because we don’t have enough creatures in the deck. I’ll take out [scryfall]Back from the Brink[/scryfall] because we have plenty of ways to recur our creatures anyhow. I’ll take out [scryfall]Breathstealer’s Crypt[/scryfall], because it doesn’t do enough in a format with 40 starting life total.
I’ll also take out [scryfall]Rise from the Tides[/scryfall]. As much as I would like to play it, I don’t think our graveyard will have enough spells to make it worth it, since we are planning on using them anyhow. I’ll take out [scryfall]Deep Analysis[/scryfall], because we’ll have plenty of things to do with our mana without drawing cards. I’ll take out [scryfall]Cackling Counterpart[/scryfall], because we don’t have that many creatures we want to target with it.
Although I wouldn’t want to take out any creatures, since we don’t have that many of them, I’ll take out [scryfall]Dralnu, Lich Lord[/scryfall], because it can become a liability. I’ll take out [scryfall]Snapcaster Mage[/scryfall], since I try to keep these budget. Finally, I’ll take out [scryfall]Toshiro Umezawa[/scryfall], because we don’t have enough ways to trigger him ourselves.
That leaves us with room for 47 manasources, on top of previously mentioned [scryfall]Drownyard Temple[/scryfall]. Eight artifacts and 40 lands sounds about right.
As you can see, I have emphasized things I can get into my graveyard here. We do have some ways to use them. Our handful of Delve cards if nothing else. For lands, use whatever you have available, but I would emphasize black sources quite a bit. Something like 36/24 sources would be fine. Again, you should probably use as many fetches as you can, as we can use those in the graveyard.
All-in-all, this is just a first draft of a deck I wrote down pretty much right after I saw the spoiler, so there are plenty of things I haven’t thought through here. Not many answers, for example.