There are many reasons why you would want to make more storm and cast Tendrils for some insane amount of lifeloss. Situations like these may even come up quite frequently in Legacy tournaments: Your opponent may be holding a Swords to Plowshares, has attacked with a Batterskull, has counters on his Umezawa's Jitte, or has simply gained some life using his Scavenging Ooze or what not. In each of these scenarios, it's quite likely that you would want to cast Tendrils for more than 10 storm, even if it's just to be safe. Now you won't always be able to go for a Doomsday-Time Spiral pile, and if you can't resolve a Silence first, Time Spiral isn't a very desirable plan against blue decks or people that play Mindbreak Trap. In these situations you'd probably want to kill using a double-Doomsday pile.

Double-Doomsday piles are piles that build up to another Doomsday being cast that turn, to construct a second pile that builds up to a kill with a very high storm count.

As a basic requirement in addition to a typical Doomsday win you should remember that in general you need to produce 3 additional black mana. Sometimes this three additional mana can be either 1UU or BBB or 2R, which will be written as [1UU/BBB/2R]. However, this additional cost can basically always be payed for by mana from Lion's Eye Diamond, so generally it's not very hard to produce. Let's take a look at a basic double-Doomsday pass-the-turn pile:

LED in play, PTT:
-> TW/AoI, LED, GP, DD, BW          1UU/2R (3)         9 Storm
-> TW/AoI, LED, LED, BW(ToA), X

Plays out as follows: Cast Doomsday build [TW/AoI, LED, GP, DD, BW] Pass the turn.

  1. Cast TW/AoI, Exile (LED, GP, DD)
  2. Cast LED
    • Crack LEDs for BBB and UUU/RRR
  3. Cast Doomsday build [TW/AoI, LED, LED, BW, X]
  4. Cast GP, draw (TW/AoI)
  5. Cast TW/AoI, exile (LED, LED, BW)
  6. Cast LED
  7. Cast LED
    • Crack LEDs for BBB RRR
  8. Cast BW targeting ToA
  9. Cast ToA for 9 storm.

You have to realise that from part 4. and on it's just a regular pile. So the procedure that happened up to the point that you cast the second Doomsday has cost you [1UU/2R]+BBB to execute, but also produced [1UU/2R], which allows you to execute a regular pile afterwards. The key thing here is the unique effect of TW/AoI allowing you to save a draw through the exiled GP even when using LED for mana.

You can also use CB instead of an exiled cantrip to achieve the same effect. Let's look at another example:

CB in play, GP in hand:
-> IU, LED, LED, BW(DD), BW         1UUR   (4)         13 Storm
-> IU, LED, LED, GP, BW(ToA)

Plays out as follows:

  1. Cast Doomsday build: [IU, LED, LED, BW, BW]
  2. Cast GP, draw (IU)
  3. Cast IU, draw (LED, LED, BW)
  4. Cast LED
  5. Cast LED
  6. Cast BW for DD, hold priority and crack LEDs for UUU BBB
  7. Cast Doomsday build: [IU, LED, LED, GP, BW]
    • Crack CB targeting nothing, draw (IU)
  8. Cast IU, draw (LED, LED, GP)
  9. Cast LED
  10. Cast LED
  11. Cast GP, hold priority and crack LEDs for BBB RRR, draw (BW)
  12. Cast BW targeting ToA
  13. Cast ToA for 13 storm.

This time we have used both the fact that we have wishes and a draw effect stored to be able to execute the pile. You can also achieve a similar effect even without wishes.

Example:

CB in play, GP in hand:
-> IU, LED, DR, DD, ToA         UUBB   (4)         10 Storm
-> IU, LED, DR, GP, ToA

Of course this is much less effective due to the lack of extra 'cards' available from wishes.

All the above piles can of course be improved through addition of further cantrips or mana being available in helping facilitate greater storm counts.

Double-Doomsday without TW/AoI or CB

You might wonder whether we can execute a double-Doomsday pile without CB or TW/AoI. The answer is yes! But you probably won't ever go for a pile like this unless some very funky circumstances occur.

Example:

-> IU, GP, DD, LED, BW
-> IU, LED, LED, GP, BW(ToA)

The first problem that arises is that so far we've always sacrificed an LED in response to our second Doomsday. We did this not just to pay for the draw spells in the next pile, but also to allow the LED to be included in the second pile. If you can't sacrifice LED because you are still holding a draw spell, you will have to build your 2nd pile without it. Thus, increasing the cost of going in to the double-Doomsday procedure with another LED. So the whole pile becomes:

GP + 2x LED:
-> IU, GP, DD, LED, BW           BBB    (3)        14 Storm
-> IU, LED, LED, GP, BW(ToA)

Note that all but the first Gitaxian Probe can be payed for by LED mana, so the life requirement isn't impossible. If you don't have GP to draw into the pile but a Ponder or Brainstorm the cost is only increased by U. Two Lion's Eye Diamonds in hand before comboing off is quite a requirement, but you can also replace one of those Lion's Eye Diamonds with the Burning Wish that you would otherwise have to tutor up with Doomsday.

To give you some examples:

GP + LED + BW:
-> IU, GP, DD, LED, LED          BBB+[1UU/BBB] (6)  13 Storm
-> IU, LED, LED, GP, BW(ToA)

2x GP + LED + BW:
-> LED, IU, GP, DD, LED           BBB   (3)         15 Storm
-> IU, LED, LED, GP, BW(ToA)

Building Piles as you go

Obviously, there are many more variations and piles than I've listed here. For example, you could also consider double-Doomsday Piles where you already have the 2nd Doomsday in hand, in that case you may lower the requirements for cards in hand by including a LED or CB in the slot of DD in the first pile. The only downside is that you can't use LED to pay for the Doomsday that is already in your hand. Unless perhaps you plan to use a Brainstorm somewhere in your spell chain to put it back, before you draw it again and sacrifice a LED with that draw effect on the stack. What I'm trying to say is that once you know what spell chain you are going to use to kill your opponent, it doesn't really matter anymore how you get there. Your mana, the cards in your hand, and the cards that you search for with the first Doomsday is what you have to deal with, and together that should result in a Tendrils of Agony for some high storm count. That's exactly why many people including myself think we should not strive to create a full listing of all possible doomsday piles, but rather create a deep understanding of how to combo off using Doomsday.

Summary

  1. You can use a Double Doomsday pile to enable higher storm piles
  2. Double Doomsday piles are handy for pass-the-turn piles
  3. Be mindful of the life loss involved in casting Doomsday twice and potentially using multiple GP