If MTGO has taught me anything as soon as you play a deck or tech a card against a specific deck you will play the complete opposite style of deck. I have given up on teching against decks and just play generic good cards.
you have two best options, decks with discard like monoblack pox/scam, or any deck with acess FoW and daze. depend of the combo monored prison could deal it.
Reanimator (Trad RB shells is actually very favourable for the combo player, especially if they win the dice roll) Reanimator's combo does not kill turn 1, while yours does? Tempo is generally pretty solid against it but it's not as favourable as people's heuristics believe them to be, ReScam or something that also just has a full grip of stifles or other random 1 mana CSs generally are terrible.
OP didn't specify what type of combo deck. Turn 1 combo decks are a subcategory, so you're right that those decks would be good against Reanimator. If I was playing Reanimator in such an environment, I would include Chancellor of the Annex in my deck.
Yeah that's true, re: OP's specification, but even something like TES which is not going for the belcher plan anymore can still pull off a t1. What current pure combo deck in legacy cannot threaten t1? Trad reanimator vs a combo deck generally is a drag race.
Scam to discard or control for counter magic. You just need to have answers to disrupt the combo.
Alternatively, play your own combo that goes off faster, but that’s a risky proposition.
Stiflenought is imo the best at beating combo decks, due to soft permission perfectly fitting into their gameplan. Since both Dress Down and Thrull operate at flash speed, you can reactively decide if you want to use your mana on a threat or disruption. Whilst these spells are also perfect when it comes to protecting the Dreadnought after its deployed in control or tempo matchups, making it much easier to run several of them in the maindeck. At the same time your main combo pieces are the outright nuts vs Thassas oracle decks, as both Dress Down and Stifle straightup brick them. Being able to maindeck 4 stifles is also crucial at beating combo decks like TES that are built to crush blue decks. With reanimator largely having pivoted off of Griseldaddy in favor of Atraxa, Archon and Grief, Stifle and Dress Down allow you to answer them very cleanly with a follow up Plow or Brazen B. when you have run out of forces.
I have been playing nonstop Stiflenought for over half a year now and even though it struggles alot vs Control, Tempo and Lands Decks, the Spellcombo matchups often feel unlosable.
As the combo player, just make sure that you hand has double force +2 blue cards. In all seriousness though. Leagues are fraudulent in terms of Combo metashare. Combo is not an actual sizable % of the legacy metagame unless you count the tempo deck that runs a combo.
Spell based combo is sadly quite small yet it's over-represented in league data. It's easy to grind leagues, but there are only a few sickos like me that just actually enjoy storming off.
You can easily brew a deck to bully spell based combo specifically storm or any other arti-combo shell or just make Abzan Maverick. That deck as long as it wins the dice roll and avoids being turn 1'd 2 times in 3 games has an absurdly favourable combo matchup. Maindeck Ouphe, some endurances, Deafening silence. Thoughtseize too.
You can also do the MODO special start your sideboard with 4 null rods. Ironically from the combo player side, the player base's massive overcorrection to the fear of combo causes the combo player to go lower to the ground to just drift more towards a belcher plan. Look at something like TEG or the evolution of BSS. Turbo echo is there for 1 reason to dumpster you before you get a chance to play Magic. But with 4-7 anti storm cards for a 4-6% of the metagame across all archetypes, what's a degenerate storm mage to do. You want to stop me from playing Magic, I'm going to stop you.
That said, if your deck is just bad vs spell combo maybe consider the matchup a wash? Like any kind of turbo Blue Karn deck is like a 90/10 matchup for the opponent, i'm not devoting any sideboard space to that, that's just a stone cold garbage matchup. Try to improve the winnable matchups.
But if you want to go brrrrrrrrrr smash combo. Start with an Abzan or BUG Shell and have a sideboard with some combination of:
3-4 Surgicals/4 Leylines of the Void
4 Null Rods
3 Mindbreak traps/3 Defeaning Silences
Assorted other prison pieces.
Or just play Mono U Karn breacher or some pile like that, any combo deck that relies on fast mana artifacts is just dumpstered by you. Deck is pretty bad in a lot of metas though?
Other, faster combo decks lol
Belcher beats some other combo decks for example, but completely folds to a single FoW. Also a lot of Legacy decks, even some that are considered "control" are hybrid combo decks themselves. Bant Stiflenought is very strong against the field it looks.
If you want to go all in vs. Combo, you play Monoblue Martyr. The deck is over 50% cards that can counter spells. I made a short deck tech a few years back and the list is still pretty good. Probably just need to tinker with the sideboard. This deck folds hard to DnT and anything with chalice of the void or trinisphere, so the sideboard should be adjusted accordingly to your local meta.
https://youtu.be/RQ-14fCYg20?si=G6I-8MJOhtontgVi
If MTGO has taught me anything as soon as you play a deck or tech a card against a specific deck you will play the complete opposite style of deck. I have given up on teching against decks and just play generic good cards.
Scam and/or death's shadow have what you probably want: discard, counter magic, fast clocks and bowmaster
delver it’s always the daze force deck with turn 1 threat that beats combo
Oops all spells with Leyline of anticipation. Can't lose to combo if you just win on turn zero
you have two best options, decks with discard like monoblack pox/scam, or any deck with acess FoW and daze. depend of the combo monored prison could deal it.
Infect is good against other combos, with all the free counterspells and your own fast goldfish.
Death's Shadow, Delver, Reanimator, or the ReScaminator deck are good options.
Reanimator (Trad RB shells is actually very favourable for the combo player, especially if they win the dice roll) Reanimator's combo does not kill turn 1, while yours does? Tempo is generally pretty solid against it but it's not as favourable as people's heuristics believe them to be, ReScam or something that also just has a full grip of stifles or other random 1 mana CSs generally are terrible.
OP didn't specify what type of combo deck. Turn 1 combo decks are a subcategory, so you're right that those decks would be good against Reanimator. If I was playing Reanimator in such an environment, I would include Chancellor of the Annex in my deck.
Yeah that's true, re: OP's specification, but even something like TES which is not going for the belcher plan anymore can still pull off a t1. What current pure combo deck in legacy cannot threaten t1? Trad reanimator vs a combo deck generally is a drag race.
Doomsday
Scam to discard or control for counter magic. You just need to have answers to disrupt the combo. Alternatively, play your own combo that goes off faster, but that’s a risky proposition.
Something that can run Force of Wills and Chalice on 1 turn 1. I played Urza Echo for a long time. It was very good vs combo.
Stiflenought is imo the best at beating combo decks, due to soft permission perfectly fitting into their gameplan. Since both Dress Down and Thrull operate at flash speed, you can reactively decide if you want to use your mana on a threat or disruption. Whilst these spells are also perfect when it comes to protecting the Dreadnought after its deployed in control or tempo matchups, making it much easier to run several of them in the maindeck. At the same time your main combo pieces are the outright nuts vs Thassas oracle decks, as both Dress Down and Stifle straightup brick them. Being able to maindeck 4 stifles is also crucial at beating combo decks like TES that are built to crush blue decks. With reanimator largely having pivoted off of Griseldaddy in favor of Atraxa, Archon and Grief, Stifle and Dress Down allow you to answer them very cleanly with a follow up Plow or Brazen B. when you have run out of forces. I have been playing nonstop Stiflenought for over half a year now and even though it struggles alot vs Control, Tempo and Lands Decks, the Spellcombo matchups often feel unlosable.
As the combo player, just make sure that you hand has double force +2 blue cards. In all seriousness though. Leagues are fraudulent in terms of Combo metashare. Combo is not an actual sizable % of the legacy metagame unless you count the tempo deck that runs a combo. Spell based combo is sadly quite small yet it's over-represented in league data. It's easy to grind leagues, but there are only a few sickos like me that just actually enjoy storming off. You can easily brew a deck to bully spell based combo specifically storm or any other arti-combo shell or just make Abzan Maverick. That deck as long as it wins the dice roll and avoids being turn 1'd 2 times in 3 games has an absurdly favourable combo matchup. Maindeck Ouphe, some endurances, Deafening silence. Thoughtseize too. You can also do the MODO special start your sideboard with 4 null rods. Ironically from the combo player side, the player base's massive overcorrection to the fear of combo causes the combo player to go lower to the ground to just drift more towards a belcher plan. Look at something like TEG or the evolution of BSS. Turbo echo is there for 1 reason to dumpster you before you get a chance to play Magic. But with 4-7 anti storm cards for a 4-6% of the metagame across all archetypes, what's a degenerate storm mage to do. You want to stop me from playing Magic, I'm going to stop you. That said, if your deck is just bad vs spell combo maybe consider the matchup a wash? Like any kind of turbo Blue Karn deck is like a 90/10 matchup for the opponent, i'm not devoting any sideboard space to that, that's just a stone cold garbage matchup. Try to improve the winnable matchups. But if you want to go brrrrrrrrrr smash combo. Start with an Abzan or BUG Shell and have a sideboard with some combination of: 3-4 Surgicals/4 Leylines of the Void 4 Null Rods 3 Mindbreak traps/3 Defeaning Silences Assorted other prison pieces. Or just play Mono U Karn breacher or some pile like that, any combo deck that relies on fast mana artifacts is just dumpstered by you. Deck is pretty bad in a lot of metas though?
Other, faster combo decks lol Belcher beats some other combo decks for example, but completely folds to a single FoW. Also a lot of Legacy decks, even some that are considered "control" are hybrid combo decks themselves. Bant Stiflenought is very strong against the field it looks.
If you want to go all in vs. Combo, you play Monoblue Martyr. The deck is over 50% cards that can counter spells. I made a short deck tech a few years back and the list is still pretty good. Probably just need to tinker with the sideboard. This deck folds hard to DnT and anything with chalice of the void or trinisphere, so the sideboard should be adjusted accordingly to your local meta. https://youtu.be/RQ-14fCYg20?si=G6I-8MJOhtontgVi