[[Estrid's Invocation]] enters as a copy of another enchantment you control. At your upkeep, you may re-enter it, allowing you to choose a different target.
Note that casting it without an eligible target will void the second part. It will just stay and sit there, not triggering on upkeep.
I tried to build a deck around this card with lots of non-legendary enchantments. And found out, Sagas are particularly interesting. The crazy interaction is that Estrid's re-enter triggers before Sagas tick up.
An example match start:
- turn 2: [[Omen of the Sea]] (1U, flash, scry 2, then draw 1)
- turn 3: [[Estrid's Invocation]] (2U), gaining another scry 2 + draw 1
- turn 4: [[Binding the old Gods]] (2BG, destroy nonland), Estrid re-entered before on the Omen to get a 3rd scry2+d1
- turn 5: Estrid re-enters as the Binding, which immediately lets you destroy a second nonland. Next but still in your upkeep, both Sagas tick up, letting you fetch two ~~basic~~ forests.
- turn 6: Estrid re-enters as the Binding before it's saga counter can tick up, letting you destroy a 3rd nonland, and fetching a 3rd forest, before the original Binding finally expires.
If you managed to get a 2nd Estrid out by that point, you can have both Estrid Sagas copy each other infinitely, without ever expiring.
Also nice: [[Elspeth conquers Death]] (3WW, exile mana 3+) and [[The Eldest Reborn]] (4B, sac creature, discard, return creature/PW from any GY)
Other non-saga enchantments which I found useful:
- [[Omen of the Hunt]] (2G, flash, fetch basic land)
- [[Wingbright Thief]] (more on that later)
- [[Smothering Tithe]] (3W, opponent chooses wether they have less mana or you gain more)
- [[Revenge of Ravens]] (3B, drain 1 life for each creature attacking you)
- and of course [[Triumphant Getaway]] (1UBR, flash, heist twice, drain 2 on casting heisted cards)
Some are useful because of their on-enter effects, some are useful to stack up a beneficial ability. A Smothering Tithe times 2 makes a significant difference in speed, no matter wether they choose to have less mana for themselves or give you more treasures.
[[Wingbright Thief]] (1WU, creature, on enter reveals opponents nonland hand cards, choose one which perpetually gains "opponent draws 1 and gains 3 life" when you cast this) ... is the only enchantment creature I found worthwhile (maybe aside from [[Overlord of the Hauntwoods]]). But it's a crazy good target for Estrid! Not only does it give you intel on their hand each round for free, you can also burden their most valuable spells with an advantage for you.
For some spells, like untargeted discard, this outright renders it useless. Sure, you can cast it and make me discard a card, but before that happens, I get to draw one and gain 3 life. Similarly, red face damage can be neutralized by this.
For most other spells, the question becomes "how many stacks of Wingbright Thief can this card endure, before casting it becomes more beneficial to your opponent than to you?", which is quite an interesting game mechanic if you ask me. Both sides have to weigh options and estimate value.
Some spells remain useful regardless of how many stacks they have. When a [[Haze of Pollen]] (1G prevent all combat damage) would prevent you from dying, it's still worth casting, even if your opponent draws 10 cards and gains 30 life.
Another poweful aspect of Estrid's Invocation is the flexibility it provides. On each upkeep, you can re-spec your toolkit, choosing wether you want more creatures, more sagas, or more passive abilities this turn.
Sometimes I even use it on [[Utopia Sprawl]] (G, forest makes extra mana) to have 1 more mana this round of a missing color, or on [[Valgavoth's Lair]] (a hexproof land of any color) to have more mana next round, and to flee an expected nonland destroy.
The more I play with it (Magic Arena Historic), the more I wonder why I see it so rarely. Have you played with or against it already? What are your thoughts?
Confirmed. At first I was confused about the comments. Good idea, an obvious opportunity!