What is the lowest combination of dual-types that can resist/be immune to every single possible combination of 2 types?

Question

The lowest amount of dual-types required and what they are to resist each possible combination of 2 different types.

Basically what I'm asking is for the lowest amount of dual-types needed to have one dual-type that resists/is immune to both types of another given dual-type, and have that for every dual-type.
I'm getting confused writing this, but I hope you understand.

Thanks in advance.

Comments

So you're asking for the least amount of Pokemon that can resist any set of two different typed moves?

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Should answers account for abilities?

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Sure, abilities can count if you want, and yes that's basically what I'm asking.

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I feel like this question is confusing. Are you asking how many pokemon types in general are needed to be immune or resist any type of move? Then like it said before abilities are valid? Cause if your asking for that then you really only need levitate electric type. Which Eelektross already does. Its only weak to ground and levitate doesnt work. If you want it with only typings do you mean HOW MANY TYPINGS IT NEEDS TO BE? Cause it was a little confusing. Ex Using Trick o Treat makes the enemy have ghost typing if it doesnt already have it even if its a dual type

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Eelektross doesn't resist all types there's just nothing super effective against it

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This is asking about existing Pokemon, not type combinations, right? I can't say the answer includes a normal steel Pokemon?