Trevenant
Trevenant are basically the Poison Ivy (as in the DC supervillain) of the Pokémon kingdom. They can control other plants (mostly trees) and literally curse anyone who harms plants.
However, that raises the question of how Trevenant treats people who worship nature, especially plants and trees.
In the UK and other European countries, May Day is a long-running holiday with roots (pun intended) in pagan religion. The traditional holiday celebrates fertility and the changing seasons, and the maypole is a constant feature in May Day festivities.
People dance around the pole in a rite that supposedly ensures fertility.
Imagine, if you will, a benevolent Galarian Trevenant that makes flowers bloom instead of trapping lumberjacks in forests.
Also, imagine this Trevenant evolving into a sentient maypole that attracts Grass-type Pokemon and/or strengthens Grass-type moves. The metagame would be insane.
