>>27646482Paras/Parasect was the first Pokemon I saw in the anime. I'll start by helping you out with a basic Parasect build.
Parasect@Leftovers
Dry Skin
252 Hp / 160 Def / 96 SpDef
-Spore
-X-Scissor / Knock Off
-Substitute
-Leech Seed
You absolutely want a Drizzle partner in the form of Politoed or Kygore if legends are allowed to abuse Dry Skin's auto-healing and to mitigate Fire damage (you'll still probably die even in the rain). Substitute + Leech Seed is a basic annoying stall strategy. Take advantage of Spore. It is Parasect's only saving grace. X-Scissor is for putting the hurt when needed on Bug-weak foes. Knock Off is probably a better option because it is so universally good.
I don't know if you and your friend do doubles. If Doubles then swap Substitute for Rage Powder and Leech Seed for Protect.
Partners needed are:
+Politoed (Kyogre) for auto-Drizzle
+Offensive Swift Swim like Ludicolo, Kingdra, or Kabutops
+Rock resist (Steel or Ground type)
+Fire resist (Flash Fire mon maybe?)
+Flying resist (Steel type most likely)
+use the best possible Mega-evolution you have access to
Hope this puts you on the right path.