Lil' Sunny

I finished the game with a Dark monotype for my last run, and I can assure you that the term of 'easiness' is purely relative. For example, I know Electric monotyper are doomed against Solaris's Garchomp in Pyrous Mountain, and I still have some sweet memories of Shelly and Bennett bugging me while I used Spiritomb as a starter  But hey, as long as you do it with a Pokemon Type you like, you don't have to regret anything. Just keep remember that you can still use the field effects to your advantage in Reborn. Of course, it all depends on the Pokemon you've found 

@not Azery owo I once tried doing a fairy mono and got bored after beating Shelly, and now I'm doing a psychic mono which has been a bit more fun but still hard compared to my unlimited run. guess it has to do with experience xD

I call it easier because on a normal playthrough, you tend to only use one of each type of Pokemon on a team for example, so if that one falls, you lose a huge amount of coverage. Not nearly as prevalent in monos imo. Definitely relative with experience though.