I'm not a big fan of trying to Iron Head hax with Rachi in Ubers. It's just so weak and spreading para is meh for a stall team as it doesn't have the fire power to take out the crippled threats. Toxic/Protect/Wish/U-Turn or SR or some other filler is my favorite way to run Spdef Rachi. There is also SpDef Latias that can switch into anything M2 wants to use and stall it out or KO with Dpulse. TTar can Pursuit trap it if you can get it in safely. Otherwise you just prey on its weakness to passive damage and lack of switch-in opportunities by forcing it out with checks.