Something else I've been experimenting with, that I'd like some feedback on - I have a second Rotos that I haven't built out yet. My original plan was to build him basically the same as my first one (standard nuker), and run him on my second speed nuke team - probably something like Kymar + Kimi + the two Rotos. Also, potentially, to run him against their primary speed nuke team if their nuker is a big single-hit nuker like Genbo.

But lately I've been running him on my go-second team, instead of Mortu, and I've had quite a bit of success. The extra turn gimmick lets me avoid most of the really dangerous nukes, and once he starts rolling his A2, he becomes both a primary target AND very hard to kill, taking a lot of the heat off of Raglin.

Think it's worth building the second Rotos with high resist, and running him on that team instead of Mortu?

I don't know about instead of Mortu, but I'd build a 2nd either way lol.  As I know you are aware, Tag isn't about having 3 teams for offense it is about mixing and matching for each opponent.  I am lazy, so I use the same go 2nd team 80% of the time when I should be swapping much more often.  My other 2 teams though I have 12-15 I use as needed.  Building a cardinal team finally, so my arena options will expand significantly soon.  And I am building Kimi and Kymar dupes as well.

Yeah I hear you, just that the builds are different - if my plan is for Rotos to be on that speed team, I won't be bothering with resist.