Yesterday marked the transition point from Cobalion to Terrakion as raid boss at the Tier 5 level. It was received with gladness by local raiding fans, as the outgoing boss was less relevant in the meta, so to say.
GoHub has a good general-info page for Terrakion here:
And a pretty good best-counters page here:
Note that the lowest weather-boosted CP is correct on the third page’s infographic, but the first page differs:
2553 – 2641 (Boosted Level 25 raid catch in Cloudy and Partly Cloudy)
Whether that was an error or just a typo, I knew it was off when my first raid (weather boosted) got this: