Best Theoractical Matchup?
Double ground Flygon VS double electric Magneton. This is the one I can think of.
Triple resistance + double effectiveness.
Can you give a better one (quadruple resistance + double effectiveness) or a different matchup as good as the one mentioned above?
Answers
There is no such thing as quad resistance, as that would require two immunities. There is no type in Pokémon to which two opposing types are immune. As such, immune+resist is the best you can get, of which there are plenty of options.
From an attacking standpoint, double effective is the best you can do.
Therefore, your match up is the best possible. There are other examples, but they are limited. Im not sure there are any existing examples. Mawile going against a dark/dragon (Gen 5) is a future one.
Pantanimial summed it all up, but an even more intuitive explanation is that every type (if given an immunity) is given exactly one unique immunity (Except ghost), therefore by extension, there is no possible case where two immunities can stack. (EDIT: I realise you said the same thing lol)
There are plenty of double resist and double SE I think, most involving the flying typing and or fire typing as they both hit into the same types effectively (bug, grass) and both resist their moves double effectively.
Just by playing around there is double fire charizard (also moltres) vs double bug scizor, double fire charizard vs double bug forretress, maybe others can come up with more, but of course these are 'less optimal' theoretical matchups.
I don't think that would be possible. The closest I've done myself in a real raid setting is double-bug Scizor against Exeggutor. I'm pretty sure I could've beaten that raid with just the Scizor at ~2000 CP, but even then the boss would be "just" 7 times the CP of my Pokémon. I could be wrong though.
Edit: oh right, the weather bonus. Still don't think a 1400 CP Flygon could quite do it.
