Rule 903.11 - essentially states if it's fine to play cards from outside the deck the must meet color ID, not have the name of a card you own in play or in your original 100 deck - hence why I may include Spawnsire

Problem is the RC of EDH specifically bans wish effects, citing 3 reasons
1. Assymetrical usage - If someone gains control of a wish effect but doesn't have a wish board then it's dead in the water
- Applies to Spawnsire but the likelihood of them running Eldrazi outside the game in the first place is extremely low, it's no different than getting control of a card that you have to pay the mana cost of but aren't able to produce that mana as it's outside the color identity
2. Leads to narrow specific answers kept in the sideboard that may not normally be run in the maindeck as it's too narrow
- Nonapplicable to Spawnsire as beyond grabbing specific Eldrazi answers the point of spawnsire would be to vomit out a bunch of Eldrazi for either the win, or an attempt at the win (interestingly Maskwood Nexus theoretically works w/ Spawnsire as it applies to creatures you own but not on the battlefield)
3. Violates the 100-card exactly premise
- Our playgroup already violates that with some regularity, often unfinished decks are allowed several more cards than they would otherwise run - at best it can be argued these are specific exceptions and do not apply generally, but then it must be allowed to at least test Spawnsire's effect to see its efficacy, much like how others test the efficacy of specific cards in their larger-than-100 deck

The neutering of the learn mechanic was also dumb AF imo - Assuming you're deck's ID is GB you can get access to at best 10 mediocre sorceries or instants which are outshined by better cards in green or black and can be tutored more easily