>>50694249XY's show has its climax around Zygarde and probably the best example you might be looking for. SM show has a lot of exposure on the Tapus, UBs including Ash battling with a Naganadel and Melmetal. The current series just recently had the Arceus special featuring lots of the Sinnoh legends.
There are many other scattered appearances but some of them aren't really remarkable. I'll leave it with the baby Lugia episodes.
