||1. Tap Tundra to Cast Mystical Tutor and Dont let It resolve - 0 2.Trigger Birgi and let It resolve - R 3.Tap Volcanic and Mox to Cast Valley - 0 4. Trigger Birgi and let It resolve - R 5. Keep Holding prio on Mystical and Cast Mana Vault and Mox Opal 6. Trigger Birgi twice and let It resolve - RR 7. Cast Chormatic Star -R 8. Trigger Birgi and let It resolve - RR 9. Keep Holding prio on Mystical, Tap Mox Opal to Cast Enlightened Tutor and Dont let It resolve - RR 10.Trigger Birgi and let It resolve - RRR 11. Holding Prio on all Cast Flare of Duplication, sac Birgi,targeting Mystical - RRR 12. Resolvé the Flare and the copy of Mystical Tutor, search for DR - RRR 14. Hold prio on Enlightened. Use R to crack Chormatic Star floating B and drawing a card (DR) - RRB 15. Resolve Enlightened Tutor, search for Necropotence - RRB 16. Hold prio on Mystical, use RR to crack the clue to draw a card (Necropotence). - B 17. Resolve the Mystical and search for Sevinnes -B 18. Cast DR and Cast Necropotence - 0 (untapped Tarnished and Mana Vault) 19. Pay 8 life to exile 8 cards with Necropotence (One of them being the Sevinnes) 20. Go endstep, Sacrifice the Breach and take the exiled cards (Necropotence) to your hand.8 cards in hand - 0 mana (untapped Tarnished and Mana Vault 21. Go to clean phase (RCoE effect ends). Discard any card that IS not the Sevinnes. 22. Necropotence trigger. Cast Sevinnes in response to the trigger targeting Breach. Loop Lotus Pétal with Brain Freeze.||

@sendowiis your solution doesnt seem to work, note these steps ||19. Pay 8 life to exile 8 cards with Necropotence (One of them being the Sevinnes) - you will die if you pay 8 LP 22. Necropotence trigger. Cast Sevinnes in response to the trigger targeting Breach. Loop Lotus Pétal with Brain Freeze. - based on sequenceing i am under the impression you are tapping tarnished for colored mana, which will cost you a additional 3LP||