I hope that his predictions don't come true fully.

Then, there are really hard days waiting for us. It's a good opportunity to accumulate of course especially for HODLers. But short-term investors wouldn't be so happy about this. However, this is just a prediction in the end. There is no guarantee for all of it to happen.
Even if it does come true, the best that we can do is just wait for it, he did predict the last crash but the prices did recover right? So my suggestion is either wait it out if you have invested in bitcoin recently. Yes there is no guarantee but the possibility is endless unless something happesn that prevents that possibility from happening.