hi my internets poop right now and im tired so i'm just gonna c/p some stuff i already wrote about triples elsewhere.
despite being kinda new to triples, i do have years of experience with doubles, so i like to think i can at least hold my own. from the ~25 battles i've already done (i think i might be over 1600, which is nice), it seems like a lot of the big hits come from sylveon's and mega gardevoir's hyper voice. the official usage reflects this, too:
http://3ds.pokemon-gl.com/battle/4/ , with hyper voice and gardevoirite being the most used move on both pokemon, along with the fact that they're both in the top 12. heatran and aegislash are probably in the top 12 to help check the two as well as to take on kangaskhan, which is obviously going to be high in usage wherever you go on battle spot. so far though, kang hasn't been /too/ impressive, at least in my opinion, but that might just be because i naturally carry 1-2 intimidators with me at all times and i've learned to respect it. also, hitmontop at #1 is pretty great, but if i had my way with the usage numbers, greninja would be nowhere on the top 12 and talonflame would be slightly lower.
speaking of respect, i gotta give credit to the occasional mat block greninja and beat up+justified teams that occasionally pull a fast one on me. you seriously can't misstep against these teams, or you WILL be swiftly 6-0'd. of course, they can be easily disrupted (fake out and follow me), but they certainly command some degree of respect from me. not that i won't get salty when i fall for it (i did NOT see scarf zard+justified megaluke coming), but you know.
on a more serious note, trick room is more deadly than ever. in doubles, you kinda had to balance support with power, not allowing yourself to be too bulky to the point where you couldn't actually do anything, but bulky enough to set it up in the first place. in triples, you can keep one of the setters tucked away in a corner, have some setup in the middle or on the side, and have a powerhouse in the middle. you can even use TWO helping hands to boost your attacks to insane levels, particularly the aforementioned sylveon and eruptran (who can also make use of flash fire to make it even more ridiculous). it's been my experience in doubles that some things can't be as powerful as you want and sometimes you can't boost that mon's power effectively outside of helping hand or swagger+lum without taking more than one turn to do so, and i live by the philosophy that if you can't do it in one turn it's not worth doing. in triples, you can get all that power in one turn, which practically makes me salivate to think about, granted, you have to be in the center to receive multiple support moves, but trick room is definitely a playstyle that enjoys this option.
other aspects i think are rather interesting include the shift mechanic and moves that can hit the entire field. the shift mechanic can actually be useful to tuck a pokemon away in a corner (which will probably be your big bruiser) for some degree of protection, though this does go off the ordinary turn order, i.e. shifting has +0 priority like the vast majority of moves. ally switch is a buffed version of this, though i will say that it isn't as impressive as i would like, but this might be because i was trying it on hawlucha, which was much more useful for using sky drop anyway. speaking of which, sky drop is one of the many moves that can hit far corners. this is probably one of the reasons why talonflame is so used (brave bird and a bunch of other flying moves are on the list
http://bulbapedia.bulbagarden.net/wiki/Triple_Battle#Effect_on_moves ) since it has some degree of safety in a corner as opposed to other formats where it's liable to be hard countered by rotom and rock types. sky drop has been pretty great for board positioning too, but sky drop in general is a pretty great move so yeah. i'm sort of curious as to why wide guard+sky drop aerodactyl hasn't shown up yet.
also: the 'team' i'm using right now is
volcarona @ coba berry
modest
rage powder/overheat/bug buzz/protect
mawile @ mawilite
adamant
play rough/iron head/sucker punch
landog @ choice scarf
adamant
EQ/rock slide/knock off/u-turn
cresselia @ sitrus berry
sassy
trick room/helping hand/ice beam/psyshock
hitmontop @ rocky helmet (probably gonna change to lum or somethin)
adamant
close combat/helping hand/wide guard/fake out
hydreigon @ choice specs
modest
dmeteor/fire blast/dark pulse/dragon pulse