Setting up the shader with the mask
Rough Blockout
Figuring out 'color over life'
Changing how the mask appears (now it's local instead of UV)
Experimenting with fresnel for outward moving circles
Adding a nature element
Final Finetuning; Particles spawn shape, kill collision box and timing
Made another sketch
Duplicated the Niagara System
Moved it in scene and figure out how to rotate the mask (I had local space to false)
Moved the spawn torus way up
Adjusted pull on the particles and timing to fit the original Niagara System
Made a glow material for the plants
Full Niagara System
Animated glow in Sequencer
Added the Niagara System in the Sequencer
Made a trigger box with a blueprint triggering the Sequencer
I started off with not knowing a single thing about VFX in Unreal and so I've come a long way.
I've learned about:
Niagara Systems
Shaders (settings, parameters, animating)
Using the Sequencer
Making a blueprint
I've also grasped VFX in Unity better, which you can see here: