What triggers Prismana flow?

The flat rate is the part that changes how you play. Regional prismatic energy does not weight the roll, so parking yourself in a high-energy zone buys you nothing on the trigger itself. Every nurturing action has the same chance as every other nurturing action, and every catch attempt has the same chance as every other catch attempt. Volume is the only lever you have.

That makes Nurture the thing to keep doing rather than the thing to do once. Nurturing cultivates an area to generate Prismana energy, it helps you actually capture a Prismana Aniimo once one shows up, and each action is another roll at the same odds. Catching runs on the same flat rate per attempt, and capturing many Aniimo in a zone lets you release Prismana energy there.

Worth knowing before you chase it: different forms of the same Aniimo share identical base stats, and Prismana variants are not inherently better in stats, moves or abilities. You are chasing a rare radiant version of a Nova-stage Aniimo, and in some cases a form-exclusive skill, not a straight power upgrade.

Lucky Strikes while catching

Catching has a second route in. A Lucky Strike during a catch awards items, raises prismic energy in the surrounding area, and has a chance to immediately trigger a Prismana flow. So a catch attempt can reach a flow either through the flat base probability it always carries, or through a Lucky Strike landing on top of it.

Weather as an indirect route

Specific weather conditions can trigger Prismana spawns in certain locations. Nurturing lets you change the weather, which means Nurture feeds the same goal twice over: the direct flat chance on every action, and the ability to set the conditions a location needs. Aniimo also have weather-based forms and other variations that are separate from Prismana variants, so a weather form appearing is not the flow firing.

Not settled: Whether a Lucky Strike's flow trigger is a separate roll from the flat per-attempt chance, or the same chance surfacing in a different way, is not settled.