I'm in Ieyasu Tokugawa's storyline, and I've taken over the whole map but one square. I have 97/100 pokemon to complete, and I'm just milking it for evolutions for my warlords. I read that the way to get Registeel to appear is to have 15+ warlords with Perfect Link, and I'm not sure how picky it is about that - does that mean they have their best link in party, have had in the gallery, have it active, have it at 100%, or what? Any info about this would be sweet.
Should be like this, from what I gathered after I request the same question yesterday: First, you need to complete Ieyasu's storyline once. It's one of the 3 requirements for unlock Registeel, so you can't get it the 1st playthrough with him as MC. Then you need 15+ Warlords with Perfect Link (should be in the Gallery).
Achieved this 2 requirements, start an Episode (or re-do Ieyasu Episode, so you are sure he is in your active team), go to the Nation that Legendary appear (for Registeel: Valora), upgrade both farm facilities (the area where Wild Pokémon appear) to level 3 or more and just wait until Registeel's event happen (random chance every start of month). --- sorry for bad English, it isn't my first language >.<