Ur late: Double Trouble
Phase 1: https://m.youtube.com/watch?v=7Wn3bZpqABQ
Phase 2: https://m.youtube.com/watch?v=qiebxxRlfQQ
Phase 3: https://m.youtube.com/watch?v=nR83rcQDXjw
Phase 4 (Route A/Filibuster dead, you fight Sans): https://m.youtube.com/watch?v=sk2UrDH_Ey8
Phase 4 (Route B/Sans dead, you fight Filibuster Obstructa): https://m.youtube.com/watch?v=yTKrs02jAS0
Phase 5 (Route A/Filibuster dead, you fight Sans): https://m.youtube.com/watch?v=0aNGVCLUw2Q
Phase 5 (Route B/Sans dead, you fight Filibuster Obstructa): https://m.youtube.com/watch?v=CsGFV46O98A
Remember: this is not Sans vs Filibuster
(I do this again without context... again)