So, I'm considering doing a Hypixel Skyblock lets-play blog where I take random challenge ideas and add one for every milestone I hit (e.g. Skyblock Levels, major skill levels, collection progress), and I need some challenge ideas.

I'm going to be doing it on an Ironman profile (to ensure that I don't get thrusted into over 10 challenges quickly).
They can be anything, including using a resource pack (I won't use ones that require Optifine), not being able to have a certain item, no using a certain minion, and so on.