Placing event Pokemon

[ssbCasper]

Greetings. Question is relatively straight forward. How would you go about distributing event Pokemon to specific areas in a game. I determine event Pokemon based on these 3 things 

• Unique early game Pokemon that people wouldn't use under normal circumstances (An example would be the Kricketune in Periodot) 
• Strong Pokemon that bridge the difficulty and make the game feel a bit easier (An example would be the early Ralts from a few episodes ago)
• Pokemon that fit into a side quest or small event that would happen in that area (Examples would be most wasteland event Pokemon) 

 

So far that's how I've been placing event Pokemon into my game. If anyone has a different idea for when or why a Pokémon should be placed in an area feel free to let me know. 

[Seal]

-Pokemon may be to strong/unique/rare to find in the grass.

-To give people a different experience catching Pokemon.

[Star Arcana]

I think, depending on the nature of the event, that having the player meet certain requirements (catching X number of Pokemon, finding X number of collectibles, ect) also adds a certain experience to the game. It may get the player to do things they wouldn't otherwise have done (bothering with the collectibles, for example)  and rewards the players that do go through the trouble of finding collectibles, catching lots of Pokemon, ect. 

 

Event Pokemon could also be a good way of introducing a species that doesn't fit in your dex, or that you would rather players not get multiples of for a while (for example, having an Eevee event earlier on, as it makes a good fit, but having the daycare come much later).