https://pokepast.es/6ab3d330d9d72469 *I mean to replace Freeze Dry with Spikes, sorry for the inconvenience.
Kabutops -
The main reason I built the team is that Fossil Pokemon. Kabutops has a ton of versatile sets like CB, Life Orb, Rocks + Rapid Spin, and Swift Swim sweeper (the one I chose). So I mainly decided to follow mainly that archetype & tried to come up with many things which'd greatly benefit from the Rain. Rockium Z is a good addition to Kabutops because it helps destroy Slowbro, Heliolisk, & Vileplume which are it's main counters to the team.
Liepard -
This mon doesn't get used that often in NU, so I decided to bring it back from obscurity and made it one of the Rain setters on my team. Damp Rock helps my Rain last longer. T-Wave & Knock Off are great support moves that cripple the opposing team to support Kabutops endeavors. U-Turn pivots it out of no good situations and makes it less passive. Xatu & Liepard form a good core as Xatu pressures Fighting types and Liepard pressures Rotom.
Ludicolo -
This is the bread of the team. It helps the team versus Bulky-Water types even further with Giga Drain . Substitute grants it more longevity & it's good against passive foes. Hydro Pump gives Ludicolo power to push through some opponents & Ice Beam is just coverage for Flying types & Grass types.
Heliolisk -
Greatly fits into the rain team with its ability Dry Skin which gives it a source of recovery in the rain. It forms a VoltTurn core with Xatu & Liepard. It's a great wallbreaker and one of the best Pokemon in NU right now with STAB like Hyper Voice, Thunderbolt, & great coverage like Surf (benefits from the rain), Grass Knot, Dark Pulse, & Focus Blast.
Xatu -
Keeps hazards off my field, beats Ferroseed (one of the main nuisances to my team), gives off Rain just in case my Liepard is either KO'd or in a state where it can't be on the field. Beats Steelix 1v1 and other rockers.
Glalie Mega -
This greatly benefits from rain like Heliolisk because it doesn't get crippled by Fire Attacks & cripples Fire types. This is my go-to Vileplume check that can OHKO it with STAB Return because Vileplume is a bigger nuisance to the team than Ferroseed. It also provides Hazard Control for the team because it lacks Hazards in the form of Spikes.
In conclusion, this team pressures all of its checks & counters by supporting each other with its kill-power. Each of them greatly benefit from one another.