Okay, now that im back writing analysis, I decided to write this set that I came up with and tested extensively, and it has worked absolute wonders for me.
www.smogon.com/dp/pokemon/roserade
[SET]
name: Life Orb
move 1: Sleep Powder / Hidden Power Ground
move 2: Leaf Storm
move 3: Sludge Bomb
move 4: Synthesis
item: Life Orb
nature: Modest
EVs: 252 SpA / 4 SpD / 252 Spe
[SET COMMENTS]
<p>This set is meant to give Roserade more longevity, without reducing its ability to deal massive damage to your opponent. This set excels at wall breaking in its own way, by preventing recovery by slower Pokemon such as Chansey with Sleep Powder, limiting the amount of times they can switch into a STAB Leaf Storm. For example, if Chansey switches into Leaf Storm, it will be put to sleep before it can use Softboiled, giving you a free turn to switch and scare it away. Now, all you need to do is rinse and repeat until Chansey is in KO range, and depending on your damage rolls it could possibly even be Chansey's second switch-in. Substitute is a decent option to ease prediction as well, though having a recovery move is usually much more important.</p>
<p>On top of having enough firepower to beat Chansey (albeit in two switch-ins), Roserade also possesses some nice special bulk and a recovery move. Synthesis is recommended so that you aren't forced out immediately after you recover, which makes sure you aren't set up on. Rest is a viable option because of Natural Cure, allowing you to fully recover regardless of weather conditions as long as you are willing to switch out. As an alternative to Sleep Powder, Hidden Power Fire or Ground can be used to hit Registeel for super effective damage, and with Synthesis, Roserade can actually beat Registeel. However, Sludge Bomb is generally superior to Hidden Power due to having high base power and STAB for late game sweeping.</p>
<p>The recommended EVs for this set are simple, maximum Special Attack and Speed. These help Roserade outspeed most Life Orb Moltres, and neutral natured base 85 Pokemon, while retaining the firepower needed. Alternatively, you can use an EV set like 144 HP / 252 SpA / 112 Spe. These EVs for this set are made to give Roserade a decent amount of bulk, with just enough Speed to be effective. 112 Speed EVs allows Roserade to outpace Pokemon such as Blaziken and Honchkrow, and Special Attack needs to be maximized for maximum damage. The rest of the EVs should be put into HP to give Roserade some much needed survivability, making Synthesis more effective. With 144 HP, Roserade will avoid a 2HKO from Milotic's Ice Beam most of the time, making it a near flawless switch-in.</p>
<p>This Roserade set benefits from similar Pokemon to the other sets, although it is capable of being effective on its own. Fire-types, Registeel, and Regirock are able to take Fire and Flying-type attacks aimed at Roserade. However, this set also requires a Pokemon who can OHKO Chansey without any set up, so that after it is slept by Sleep Powder, you can force Chansey out before it recovers HP. Pokemon like Blaziken, Hitmonlee, and basically any strong Fighting-type can do this job.</p>
<p>Offensively, Pokemon like Espeon and other specially oriented Pokemon enjoy having Chansey out of the picture.</p>

www.smogon.com/dp/pokemon/roserade
[SET]
name: Life Orb
move 1: Sleep Powder / Hidden Power Ground
move 2: Leaf Storm
move 3: Sludge Bomb
move 4: Synthesis
item: Life Orb
nature: Modest
EVs: 252 SpA / 4 SpD / 252 Spe
[SET COMMENTS]
<p>This set is meant to give Roserade more longevity, without reducing its ability to deal massive damage to your opponent. This set excels at wall breaking in its own way, by preventing recovery by slower Pokemon such as Chansey with Sleep Powder, limiting the amount of times they can switch into a STAB Leaf Storm. For example, if Chansey switches into Leaf Storm, it will be put to sleep before it can use Softboiled, giving you a free turn to switch and scare it away. Now, all you need to do is rinse and repeat until Chansey is in KO range, and depending on your damage rolls it could possibly even be Chansey's second switch-in. Substitute is a decent option to ease prediction as well, though having a recovery move is usually much more important.</p>
<p>On top of having enough firepower to beat Chansey (albeit in two switch-ins), Roserade also possesses some nice special bulk and a recovery move. Synthesis is recommended so that you aren't forced out immediately after you recover, which makes sure you aren't set up on. Rest is a viable option because of Natural Cure, allowing you to fully recover regardless of weather conditions as long as you are willing to switch out. As an alternative to Sleep Powder, Hidden Power Fire or Ground can be used to hit Registeel for super effective damage, and with Synthesis, Roserade can actually beat Registeel. However, Sludge Bomb is generally superior to Hidden Power due to having high base power and STAB for late game sweeping.</p>
<p>The recommended EVs for this set are simple, maximum Special Attack and Speed. These help Roserade outspeed most Life Orb Moltres, and neutral natured base 85 Pokemon, while retaining the firepower needed. Alternatively, you can use an EV set like 144 HP / 252 SpA / 112 Spe. These EVs for this set are made to give Roserade a decent amount of bulk, with just enough Speed to be effective. 112 Speed EVs allows Roserade to outpace Pokemon such as Blaziken and Honchkrow, and Special Attack needs to be maximized for maximum damage. The rest of the EVs should be put into HP to give Roserade some much needed survivability, making Synthesis more effective. With 144 HP, Roserade will avoid a 2HKO from Milotic's Ice Beam most of the time, making it a near flawless switch-in.</p>
<p>This Roserade set benefits from similar Pokemon to the other sets, although it is capable of being effective on its own. Fire-types, Registeel, and Regirock are able to take Fire and Flying-type attacks aimed at Roserade. However, this set also requires a Pokemon who can OHKO Chansey without any set up, so that after it is slept by Sleep Powder, you can force Chansey out before it recovers HP. Pokemon like Blaziken, Hitmonlee, and basically any strong Fighting-type can do this job.</p>
<p>Offensively, Pokemon like Espeon and other specially oriented Pokemon enjoy having Chansey out of the picture.</p>