Out of the three Galarian birds, Articuno was the most annoying to catch up with an initiate the battle. The first time it spawned just outside of Freezington, but while it was doing the spinning double team thing I lost concentration because there was an Obamasnow nearby that aggroed and started chasing me. I then had to follow Articuno all he way across the Giant's Bed and up the mountain to the little grove it stops at near Regice's temple. I saved just before Articuno started spinning, it took a few goes to get it right, but by the time I did run into the real Articuno I was so annoyed that I wasted no time and threw my last Master Ball at it.
I've decided to call it a day on my Shield Expansion Pass playthrough, because I've done everything I wanted to do and registered every Shield exclusive Pokemon into my Home Dex. At the start of December I plan on starting one more Sword playthrough before I say goodbye to the Galar Region, primarily to catch Spectrier, Regidrago, and any Sword Expansion Pass exclusive Pokemon I don't have yet. I'm thinking of running a team that combines some Pokemon I've used in my past playthroughs (like Corviknight and Sandaconda from my first Sword run, Boltund from my first Shield run, and Blastoise from my most recent Shield run), effectively an "All Stars" team, but I may also add some Pokemon I've never used before like Centiskorch and Galarian Slowbro to keep things fresh.