Here's a guide that explains the safer strategies for speedrunning High Hell.

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Introduction: 00:00 Settings: 0:39 Mission 0: 2:38 Mission 1: 5:43 Mission 2: 6:23 Mission 3: 9:43 Mission 4: 13:31 Mission 5: 16:00 Mission 6: 17:08 Mission 7: 20:22 Mission 8: 23:16 Mission 9: 24:57 Mission 10: 28:16 Mission 11: 30:03 Mission 12: 33:11 Mission 13: 34:55 Mission 14: 40:20 Mission 15: 45:00 Mission 16: 47:13 Mission 17: 50:15 Mission 18: 52:45 Mission 19: 57:50 Mission 20: 1:02:50 BO$$: 1:06:05