Jovy shapes them from a phosphorescent matter he brings ex nihilo.
Jovy can make platforms, swords, barriers, handcuffs or furniture out of them. It is a safe bet to assume he can give his blocks any form he wants.
The blocks follow a pulsating cycle of color, alternating between blue and purple. Sometimes, quick particles can be seen running in a circuit inside.
- Jovy can create a block wherever he wants. In strip 79, Klow suggests he could kill someone by materializing a block in their brain.
- A block is weightless as long as Jovy doesn't give it too much of a shock. That's why blocks can keep floating in the air, while when Jovy throws a block at Floreal during the Floreal fight, the block goes down and crushes the Familiar.
- Jovy's blocks are rock hard.
- F.A.Q. data: "Jovy’s power creates temporary, luminescent blocks seemingly out of nowhere. These blocks are not necessarily platforms; he could, for example, shape a weapon out of it. The matter is quite sturdy. (...)
At first, Jovy could only create very tiny blocks, dice-sized. But… back then, it was already a deadly power: if he wished to, he could materialize one of these tiny blocks in someone’s brain, killing them immediatly. (...) The phosphorescent, pulsating matter cannot follow Jovy’s orders. It doesn’t even “form”, it isn’t like “growing clay”: it appears out of nowhere, fully shaped, carved in the substance he makes all of his blocks in. Jovy’s power work with it as if it was selecting a part of a stone block. Once the “sculpture” (let it be a platform, a sword, a barricade, a spike, anything, really) is extracted/materialized, he cannot act on it anymore. The process is instantaneous. As with Vitriol’s power, the shape isn’t perfect. Jovy’s power generally pollutes the result with some stalactites. If Jovy was to move in a really supernatural way using his corallian gift, it would probably be by building pillars under himself, piling up block on block. He would have to be supported by Tilda’s power to accomplish such feat. Worse still, our shining hero would have to focus entirely on the task at hand. And since Jovy has the attention ability of a corgi on drugs… (...) The Level 1 limitation is only there because we didn’t want Jovy to explore the sky instead of the city. In extradiegetic terms, he isn’t interested in creating more than one platform at a time because he wants to go further, not higher. There is a limitation to the amount of matter Jovy can create in one shot, but it isn’t this tiny. He can also let blocks he already created exist in this world – he’s like the most fabulous 3D printer you’ve ever seen. (...) Jovy can create multiple blocks because he was always able to do so. And he doesn’t need to put in any effort to maintain their existence: as long as he doesn’t want them to disappear, they don’t. Back home, all of Jovy’s furniture is made in this phosphorescent matter he creates ex nihilo."