I have been modifying my Legacy format deck with the new ban list as of June 20th. This is not finished by any means, I still have to figure out how to win.
The sideboard is just what is in my normal legacy deck right now... with the exception of a couple of cards.
The Gemstone Caverns and leylines are if i feel like going second and dragging out the game. The leyline of the void dark ritual and praetors grasp infi combo is basically a joke.. its chancellor of the annex, gemstone cavern, leyline of anticipation, leyline of the void, nix, dark ritual, praetors grasp in their upkeep/main phase, pact of negation is a good one if no nix is in the hand. but its basically grab a 1 dmg spell, infi combo it. and yeah win.
but like, i dont know what to do if i dont get those, so I have xantid swarm mindbreak trap for trolling. The immortal coil win is nice if i can get them past turn two and suppress them. I also have jin gitaxis, blazing archon, and abyssal persecutor in my sideboard regularly.
the nice 4 mana combination of city of traitors with crucible of worlds is nice, it was better before the ban, so i might just maybeboard it. city of traitors is still nice, but crystal vein still exists.
Path to exile is like... i want to have it... but i dont want basic land in my deck... so i have no idea what to do about it.. like, its nice with the upkeep manuevers and split second spells allowing me to cast basically anything with no fear of anything. like Extirpate after a xantid swarm, attack with it for 0 and they cant do shit - combo all day to a casade storm or something when i path to exiled xantid. its like bitumous blast then bamf into a grapeshot or something. i would rather just sorin's vengeance them and watch them friggen cringe as i sit there not dying suppressing them.
I want to haunting echoes some shitbag decks too, so i always keep that combo with me... i would love that, like mill 20 keening stone in my artifact control, they have nothing blast ramp ritual rite of flame with bituminous then haunting echoes out of it and exile everything in their deck with a nix still in hand for those shitbage force of will users.