Spent last 2 days trying to get the achievement to notice just now - each stage 1 first half, even if there was no dmg to the bot buddy, still getting *no crystal damage bonus* slashed out. In the end i got to the core without the buddy being touched once to be devastated in the end. After the run was done, tried to see what could go wrong and noticed, first half of the floor 1, even if the buddy ain't being touched you still get the crystal damage taken slashed out. On the screen it's clear that crystal is at 100%, tried it few times to be sure.