Fantastic Voyage: Three Act Structure

Act 1 - Spore disposal
Sporophyte attacks entering battle scene and uses spore attack. After attack run away option is used and leave battle. Use pokedex to find out more about it.

Act 2 - Sperm drop
After checking only pokemon - Archegonia - an Antheridia attacks entering battle scene again and using 'sperm drop'. Once again run away option is used.

Act 3 - Fertilization
After battle the Archegonia is checked again and the sperm drop attack seemed to have lasting effect causing it to evolve (fertilize).