I rarely see Suicune on stall considering how cookie cutter stall is these days (I rarely see anything outside of that gay Mega Sableye/Amoon/Quag/Skarm/Goth) but it works very well on balance and sometimes bulky offense depending on the team. It has great overall synergy with Ferro because it can eat up Electric + Grass moves aimed at Suicune from E-Ball Manaphy, Thundy, and opposing Ferro, as well as setting up Spikes which can help Cune sweep later on. Suicune can shrug off attacks from Heatran, Zard X, Mega Zor, and Talon, as well as use most of them as set up fodder. Zard X is also a really good addition to this core as it patches up the nasty Mega Manec weakness as well as providing a switch in to Serperior, HP Fire Mega Venu, and Zard-Y. Overall, Suicune loves being paired with fat shit that can set hazards as well as a wallbreaker that can muscle through shit it struggles to break through like Ferro, Mega Venu, Mega Alt, and KyuB.
Lots of fat Grass-types such as Ferro, Mega Venu, Celebi, Serp, and Amoonguss give it a lot of issues, thus it needs to be paired with something like Zard-X or Talon which can both set up on them. Thundy and Mega Manec are really strong in the current meta which makes it difficult for Cune to accumulate boosts and sweep, as they can still muscle through Cune even at +1 (NP Thundy is very popular at the moment). KyuB just comes in for free on a CM or eats up a Scald if need be (has to be careful of burn obviously) and does a shit ton of a damage with Fusion Bolt. Kyurem-B in general is just a really big issue for most Cune teams, as it can dismantle most cores that Cune is paired with, especially HP Fire variants which can bop Ferro and Mega Zor. Opposing CM users such as Keldeo, Latios, and Mega Bro can be a hugeeee issue for it, as they can use Cune as set up fodder and hit it on its physical side with Secret Sword of Psyshock respectively.
Depends on the team really. If you're really weak to set up sweepers and need to keep shit like Slowbro, Clef, Manaphy, and bulkier variants of Zard X from potentially setting up on Cune, then use Roar. It also works really well in conjunction with entry hazards, but to be honest, what Cune balance isn't running Spikes? However, when not using Sleep Talk, you really have to ask yourself if you can afford to let Cune be complete set up fodder for a few turns, so I would only use Roar on more defensive teams that have stronger defensive cores to handle most set up sweepers, otherwise they can take advantage of when Cune is forced to Rest and use it as fodder. Sleep Talk is better in most situations because it allows Cune to accumulate boosts a lot quicker, as well as making it a lot less passive in general, which can be useful on less defensive teams.
