Escape Ladder

Escape Ladder is a spell that, when activated, creates a ladder going straight upwards. The ladder travels for 105 blocks upwards, replacing all blocks in its path except for regular air; cave air will be replaced.

When the ladder is first made, it starts 2 blocks down from your current Y level. Occasionally the ladder may have some random gaps; this is caused by there being random bits of regular air mixed into cave air. As it destroys every block except for cave air, this means you can use it to break the bedrock layer at the top of the nether(although if you're looking for a way atop the nether bedrock, there are other ways you can achieve this).