skarmory is the #1 counter to lando-t, it can take stone edges and roost up all day while setting up spikes on free turns, and if lando tries to get cute and set up a swords dance, whirlwind takes care of that. however, as mentioned above me, skarm can't do a ton back offensively, especially with intimidate as a factor, so if it comes down to a 1v1 with sd lando-t vs skarm, lando-t wins. another great checking to the dancing version of lando-t, but not the utility version, is tangrowth, who tanks whatever edgequake combo you care to throw at it, but is weak to u-turn and doesn't enjoy hp ice either. another nice check is bronzong, who resists stone edge and is immune to earthquake, but can get worn down pretty easily from u-turn due to its lack of reliable recovery. still, it's a solid answer for a good amount of time. as far as spinners go, forretress and donphan both do a pretty good job handling any lando-t, since its attacks aren't doing much and they can both remove rocks at a whim. they can't do a ton back to lando, though. surprisingly, the list of checks and counters to this thing is pretty limited. outside from what i've already mentioned, there's not much that can handle it. some people have brought up rotom-w, but your standard sdef variant is slower than lando-t, so it can 3hko with stone edge (or 2hko after rocks with sand up) and even if it mispredicts and quakes into the switch, it can simply u-turn out and try again later. in summary, there's not a lot of stuff that stops lando-t in its tracks from a defensive perspective, but for the things that do, lando-t can't touch them.