So, as we know, Lion has a bubbled gem inside his mane. It looks like this:

Which looks like the real-world mineral Bismuth:

which involves a whole lot of colors. The fandom has believed for a long time that the bubbled gem inside Lion is called Bismuth.

In Same Old World, we saw this gem:

The staircase shape of the gem, along with the multicolored hair, make it look like this gem is probably Bismuth.

Now, quickly onto the subject of gem corruption: We’ve seen that corrupted gems can be pretty huge and grotesque compared to how they probably were in their uncorrupted forms (see: Serious Steven temple, Island Adventure monster).

If the gem we saw in Same Old World, which was a pretty large gem, is Bismuth, then one can imagine Bismuth’s corruption would be pretty huge.

Here’s where the theory becomes a bit of a stretch. Gems’ bodies have been described by the show as projections of “hard light”. When a gem is bubbled, as this theory’s interpretation goes, it usually cannot form because the light cannot pass through the bubble.

Rose’s bubbles are pink, however. What kind of light can pass through a pink bubble? Pink light. So even if Bismuth were bubbled, since Bismuth is made up of many colors, Bismuth may be able to partially form around the bubble.

See where I’m going with this?

-Bismuth was a crystal gem who was corrupted – probably becoming a huge, terrifying monster.

-The CGs we know poofed corrupt Bismuth and Rose Quartz put Bismuth in a pink bubble.

-Bismuth, still corrupt, was able to partially reform around the bubble, using only pink light to form a hard light projection.

-Lion is the partial formation of corrupt Bismuth.

Something that could make this theory lose some weight is if there have been examples of gems being bubbled and contained successfully using bubbles of the same color, so if you all want to comb for that, that would be cool.