well i've been trying out this set for a while and works like hell. i'm not claiming this as mine since i've seen someone else use this set and besides i don't think anybody can really claim a set? anyway here it is:
Landorus-T (M) @ Leftovers
Ability: Intimidate
EVs: 252 Atk / 252 Spe / 4 whatever
Nature: Adamant / Jolly
~ Substitute
~ Swords Dance / Rock Polish
~ Earthquake
~ Smack Down / Stone Edge
intro: somebody posted a similar set but it's sub rock polish
overview:
landorus-t is very much similar to landorus-i but is bulkier(with intimidate), has higher attack stat, and works outside sand support. it does have its disadvantages. one is its base 91 speed. although unique and outspeeding base 90s and below, it's just not enough for a sweeper and one more thing is landorus-t doesn't get a priority like lucario's extremespeed or bullet punch. but like any other pokemon, play landorus-t to his strengths and i'll guarantee you a physical attacker that can even dent groudon, giratina and other grounded physical walls.
moves and evs:
so let's go to the evs first. as every standard sweeper: max attack and max speed. landorus-t's unique speed tier allows it to outspeed base 90s which makes it somehow unstoppable by lucario. sub is for blocking status, sponging weak attacks, scouting switch ins, and for a free swords dance/rock polish. swords dance is mainly abusing landorus-t's gigantic base 145 attack. anyone here who has used SD haxorus knows what i am talking about. earthquake is mandatory to all landorus sets and is the most powerful move on the set. smack down, although gimmicky, is the only reliable way for landorus-t to get rid of things like skarmory, bronzong and rotom-w. it is weak, yes, but this landorus is meant for breaking down physical walls opening sweeps for other pokemon like terrakion, conkeldurr, and lucario. if you want a sweeping set, go for rock polish + stone edge since the power of smack down is meh without swords dance.
other options:
well there aren't a lot of options for this set. you can replace the last move to whatever you want to counter. hp ice is the best replacement for you to reliably take on gliscor and to hit dragons who are 4x weak harder than smack down or stone edge. hp fire is a way of getting rid of skarmory and the rare bronzong but other than those mentioned, hp fire can just hit grass types who resist earthquake. you can also replace the boosting move with the hp of choice since most pokemon in the whole ou tier are 2hkoed by earthquake and stone edge.
checks and counters:
well as mentioned above, skarmory is a good check to this set with whirlwind taking barely anything from any move but hp fire. to those who don't choose hp ice, gliscor is a hard counter since it'll most likely carry ice fang and will take a scratch from any of the moves landorus has to offer. if running an adamant nature, rotom-w can outspeed and burn landorus-t with will-o-wisp or just threaten with stab hydro pump.
team buddies:
well preferably the best partner is magnezone. with magnet pull and high special attack, magnezone can get rid of skarmory easily with stab thunderbolt and gliscor with 4x super effective hp ice. magnezone also happens to resist landorus-t's main enemy, ice types. any pokemon who can set up entry hazards is greatly appreciated. jirachi can set up stealth rock and can pass wishes to landorus-t while also having a good synergy with him. as for offensive partners, i would suggest latios and/or mixape. latios can get rid of rotom-w and gliscor with draco meteor and skarmory with hp fire while in turn, landorus-t can remove threats like tyranitar, scizor and the pink blobs easily with stab earthquake. mixape can totally strike fear into anything it sees and things like gliscor? eat hp ice. skarmory? roast it with a fire move. the only down side with pairing landorus-t with infernape is that they both have weakness to water and latios will share ice type weakness.