I’m not sure at the moment. I’ve completed everything I need to evolve so probably Tyranitar. I believe we should be getting all the generation 3 Pokemon.
I was thinking of switching to L’tar but will stick to Chancey for some more time. Generally I choose the weakest of the lot to work on the rest in the group. No wonder I can’t locate the Dratini I walked as buddy and a few others.
I’m primarily keeping my Shiny Gyarados as my buddy, but I’m not opposed to switching it out at some point during the event if a brilliant idea strikes me as to why I should use something else.
For me, I would think long-range of Pokemon Generation. I’m now having Porygon2 as my buddy. When gen 4 arrives, I can immediately evolve it into Porygon-Z. I’ve already gainned enough candies for all Pokemon which have further evolutions in gen 4 except Porygon-Z.