7.Fighting or ice
8.Dragon or Fire
Just like GSC/HGSS did, the gym that you complete is strong against the next gym.
So rock (which has always been the first gym in each gen it was in).
Rock is good against bug, help from the rock type tm from the gym.
Bug is good against dark,
I'd ******** love a Dark type gym.
Dark is good against psychic.
Now Psychic isn't good against ghost but there are a couple ghost/poison's so it would be good against them (or it could just be a poison type gym.)
Ghost isn't ''good'' against normal but it's immune, so it breaks the chain again, and so does the last one,
Seven is fighting or ice, because the fighting would be a challenge, and ice type gyms are always the seventh gym leader in even numbered gens.
And last would be dragon, weak against ice, or they could switch it up and have fire as the last gym, which is strong against/resistant to ice.
Second didn't have its own water gym. Or, to be more precise, Johto doesn't - the revisit to Kanto involves (with one exception, Blaine) the same gyms with (with one exception, Blue) the same types and (with two exceptions, Blue and Janine) the same leaders.
Yes, it can be argued that Koga and Janine should count as different leaders - but Lenora and Cheren are even more different, in that they have different gyms at different positions in the order (second and first respectively.)
Yet Lenora and Cheren are not being counted as separate normal-type leaders, or else we'd have four (with Whitney and Norman.)
Nor are Drayden and Iris counted separately (the one you fight depends on what game you're playing,) but the brothers are (the one you fight is effective vs. your starter.)
1. Ground. (Probably standard fare.)
2. Bug. (A gentle difficulty spike; probably standard fare with some gimmick.)
3. Fire (Probably a bit of an obstacle for those without water types.)
4. Steel. (A defensive gym; probably something that'll give people a relatively hard time.)
5. Ghost. (Either this or the next will be a nasty difficulty spike--late gyms tend to do that.)
6. Dark. (See above, but I'd probably say they're really going to prove they don't have the kidgloves on at this point.)
7. Water. (Obligatory; probably a bit of a breather compared to the last two.)
8. Psychic. (Nightmare. Just plain nightmare.)
...Admittedly, I'm just trying to base my assumptions on stuff they haven't used yet, or types of bosses.