Things each type beats:
1 dragon bug (slowtwins)
1 bug steel (Slowtwins)
1 dark ghost (Slowtwins)
1 dark poison (Slowtwins)
2 dark psychic (Slowtwins, Toxapex)
2 fairy ghost (Mandibuzz, Slowtwins)
2 dark fairy (Mandibuzz and Slowtwins)
3 dragon grass (Slowtwins, Kril, and Rotom-W)
3 electric (Slowtwins, Mandibuzz, Toxapex)
3 electric fairy (Slowtwins, Mandibuzz, Toxapex)
3 grass (Kril, Rotom-W, Slowtwins)
3 electric bug (Slowtwins, Mandibuzz, Toxapex)
4 grass ground (Kril, Rotom-W, Slowtwins, Toxapex)
4 grass water (Kril, Rotom-W, Slowtwins, Rotom-H)

Things each type resists (metric is electric 2, water 3, psychic 3, dark 1, fighting 1):
1 fairy ghost
2 electric
2 grass ground
3 dark poison
3 dark psychic
3 bug steel
3 grass water
3 electric bug
4 dark ghost
4 dark fairy
4 electric fairy
5 grass
5 dragon grass
6 dragon bug

Overall scores:
3 fairy ghost
4 dark poison
4 bug steel
4 grass water
5 electric
5 dark psychic
5 dark ghost
6 dark fairy
6 electric bug
7 grass ground
7 electric fairy
7 dragon bug
8 grass
8 dragon grass

Might still add a bonus if a mon resists the STABs of the pokemon it beats.