>>42989139The easiest way is to look at abilities. A simple example is that Excadrill synergies with Tyranitar because of Sand Rush and Sand Stream. Tyranitar sets up sand with its ability and Excadrill's speed is doubled because of its ability Sand Rush. They also cover for a few of their weaknesses. Excadrill can have trouble with faster fire or flying types (especially with sand gone) but Tyranitar's presence deters those types from staying in. Also Tyranitar has trouble with Fairies but Excadrill keeps them away.
A more complicated example would be Hattenere and Indeedee, typically used in conjunction to set up a near guaranteed Trick Room. Psychic Terrain from Psychic Surge prevents priority such as Fake Out from happening and with Indeedee using Follow Me to redirect moves, Hatterene is almost guaranteed to set up Trick Room. A way to counter this is by using something like Stalwart Duraludon or Propeller Tail Barraskewda as their abilities ignore redirection such as Follow Me.
You just have to look at it in ways of what Pokemon you want to use, and then another Pokemon that can cover for its weaknesses/flaws and vice versa.
