SCP Foundation

A rubik's cube that erases your memory the more it becomes scrambled, and can only be reversed by solving it, despite having no memory

Rather predictable, can't say I find the idea interesting.

A card sleeve that can reincarnate any character card that you put in it, from baseball cards to yugioh and pokemon, anything you can think of

As in it creates the character? Hmmm could have potential albeit predictable.

An wide assortment of jelly beans and gummy bears that do vastly different things based on which flavor you eat

Way too vague to give any kind of feedback.

Newspeak from the book 1984, the language that affects the thoughts of its speakers. Potential backstory is that it affected a small sect of people in London who 'spread" it to other people through contact.

Well that's essentially just taking the idea from 1984 and I think something similar may have already been done.

A clock that changes time is probably entirely overblown on this site, but maybe a dice that sets back time based on the number it lands on, except, that the metric of time is completely random, so 5 could mean 5 seconds, days, hours, years, centuries, and beyond

I'd personally avoid time based SCP's like this because it gets very messy and hard to write.