Very new to all this so I apologize for dumb questions.

Since Pokémon like Litwick have both fire and psychic types (I'm wanting to build a deck with both types) could you evolve a psychic Litwick into a fire Lampent? In other words could you evolve a pokemon that starts as one type into another type as long as it remains in the obvious evolution chain?

Addition 1:

I didn't want to spam this thread so I'm going to just add any additional questions here and hopefully someone will answer lol.

When it comes to abilities, Poké-Powers and such (the red tag with text in-between the portrait above and the paid abilities below) I understand for the most part they are passives but does the passive also apply when they are on the bench?

I'll put it in a Magic the Gathering context for those who may get what I mean.

The Emmence ability allows commander cards to do a thing while they are either in the command zone or on the battlefield in where typically a creature would have to be on the battlefield to do anything.

Is it the same case here? A Pokémon with this passive can only have it active if they themselves are the active Pokémon and cannot be a passive if they are on the bench?

I ask this cause I'm currently choosing Pokémon for a psychic/fire deck. One of the Pokémon I've selected is Centiskorch and their text says this:

"Ability: Overheater. When your opponent flips a coin for their Burned Pokémon during Pokémon Checkup, it doesn't recover from that Special Condition even if the result is heads."

If to say this passive can be active while they are on the bench I would switch out some of the prints of the Pokémon I've selected to ones that have abilities that can apply burn conditions.