Some magic animations in ROM hold frame data.
In FEBuilderGBA, it can be seen as magic animation in ROM.
However, it can NOT be used like battle animation.
It is made as a collection of very small frame data.
The magic system works by combining these small data programmatically.
Rewriting may produce unexpected results.
For example, some animations share palette data and share actions.
Instead of changing the animation in the ROM, it is better to introduce a magic expansion patch and create animation.