It is likely a combination of different particle effects.

A particle effect is a graphic effect which consists of many tiny objects which move according to specific rules. In this case it looks like they combined some particles which orbit around the center with some which are created at the center and move out of it while becomming more transparent and others which move towards the center while becomming less transparent.

For the rendering of the particles themself they likely used lots of shader effects like blur, bloom and different transformations.

It is likely a combination of different particle effects.

A particle effect is a graphic effect which consists of many tiny objects which move according to specific rules. In this case it looks like they combined some particles which orbit around the center with some which are created at the center and move out of it while becomming more transparent and others which ares spawned outside and move towards the center while becomming less transparent.

For the rendering of the particles themself they likely used lots of shader effects like blur, bloom and different transformations.