I started to build around a core of Mawile, P2 and Chandelure.
Mega-Mawile is one of the best TR sweepers in the game with a good pre-mega ability in Intimidate, good bulk (lives for example -1 252 Atk Garchomp Eq) and the highest Atk stat in the whole game. The EVs are standard and Fire Fang is better than Knock Off in this meta because of Z-Crystals and the huge amount of steels.
P2 is imo the best TR-setter with huge bulk and a pretty good offensive presence. The EVs are used to live 2 252+SpA Tapu Lele Psychics in Psychic-Terrain and to hit as hard as possible.
Chandelure is the second TR-setter and it is also used to counter Blaziken which is a problem for the two others. Shadow Ball and Overheat for Stab and Memento is used to sacrifice itself to let Mawile set up a SD more easily. Another option instead of Memento is Haze which allows you to stop Eevee-Pass and Set-up sweepers (especially Volcarona and MGyara).
Since my Team so far got demolished by Heatran I wanted to add some answers to it.
The next Pokemon I added was Nasty Plot Thundurus-Therian. Thundi acts as a Wallbreaker and also lategame sweeper. With Z-Focus Blast it can take out MKang which could otherwise stall out one turn of TR with Fake Out and it is in general nice to have a check to MKang. Thundi is also good against Celesteela, CharY teams (+2 Z-Focus Blast OHKOes most Hippos, Tbolt OHKOes CharY), Sand Rush and the best thing: All-Out-Pummelling Nasty Plot Thundi-T beats almost every stall team. Most Thundurus run HP-Ice coverage but I chose Sludge Wave instead to be able to OHKO Tapu Bulu and Koko and to hit fairys in general very hard because I felt like I had a good matchup against Ground-types and things like MMence.
To help out with my Mamoswine weakness and to have another option against Blaziken, Lucario, Hippo, Salamence, Sand Rush, Volcarona, CharY, Xard, Landog, Garchomp and so on I added Defensive Gyarados. The spread is just taken from the Smogon analysis. With Twave I have another option of speedcontroll and to get some Hax going with Waterfall and Para, Taunt is imo necessary on every team and beats lots of Aegislash which I troubled with so far. Btw: The synergy between DefGyara and Thundi-T is great and when you face stall you almost directly pick both of them.
The last Pokemon was previously a SubDisable Tapu Bulu but I had huge troubles dealing with Venusaur, Z-Aegislash, Heatran and wanted another answer to Sand Rush because it became quite popular. That is why I changed Bulu to a quite special Landog. It lures in Venusaur and just OHKOes it with Z-Fly. Since my team had no switch-in to Spore and Breloom just beats the whole team because it is very slow, I EVed Landog to outspeed Breloom and set up a Sub on the Spore (they always use it turn 1 if there is no switch-in for it) and then you can beat it with Fly and an EQ. The EV spread also allows you to set up a Sub to take Aegislashs Z-Shadow Ball, use one SD, take the Shadow Ball and Shadow Sneak and OHKO with EQ (I was afraid of WP Aegi and thats why I wanted to ohko it). The spread also allows you to take 1 252+ Atk Mega-Mawile Play Rough, 2 252+ Atk Mega-Mawile Sucker Punch (~92% of the time) or 1 Play Rough + 1 Sucker Punch at -1. Furthermore there is a 68,8% chance to OHKO 252 HP/0 Def Mega-Mawile with EQ at neutral.

Threats to this team are:
Gliscor: If he doesn't come in against P2 with TR up it's gg most of the time (HP-Ice on Thundi-T might help a little bit but it's nor really worth it imo)
People you faced before and they have Breloom: You need to play the Sub-Spore games correctly because they know you are Sub-Landog.
Hax: This team is quite weak to hax in the form of Crits and flinches outside of TR because most times you move last.
Substitute: Sub, my favourite move in this meta, is unfortunately quite good against the main sweeper Mawile because they can predict Sucker Punch and get up a free sub.
Volcarona: Volcarona has the potential to sweep if it is a Roost + QD variant with Firemove + Z-Giga Drain. Ways to beat it are Sucker Punch (deals ~75% at neutral iirc) and Gyarados in TR (OHKOes the standard set with Waterfall) or a Chandelure Overheat crit.

Some hints:
If they lead sth like Gengar, Tapu Lele, Tapu Koko, Tapu Fini or other common Taunt-user against P2, go for an attack 1st turn because you aren't 2hkoed by them the most time and you get an almost free kill.
Tapu Koko (in Electric-Terrain) and Thundi-T don't OHKO Mawile with unboosted Tbolt.
Thundi-T isn't 2HKOed by Kokos Dazzling Gleam most of the time.
+2 MMawile OHKOes most Hippos (most I see are SpDef).
At -1 252+Atk LO Blaziken HJK and 252Atk MLucario CC don't OHKO P2 from full.