I had a headstart being in Japan (spin 5 stops), and managed to complete it today after about 3 hours of walking/searching/battling.
The tricky annoying part is with part 4 where you have to battle each leader once. You may end up battling the same leader again, and of so… You gotta look for 6 more grunts to battle. Luckily I only had this misfortune once.
Giovanni himself was decent, but after my first defeat I did him in. He had Persian, Rhydon, and Articuno.
Afterwards, it gave me a chance to capture Articuno itself, got it on my first ball (horrible stats🤢)
I imagine he’s available in three varieties, one for each legendary bird Pokemon. Should be fun to get the others. But oh so much fighting!