[Overview]    
<p>While Regirock appears to be an inferior option in   OU due to its bad typing, which  gives it  weaknesses  to common   Grass-, Water-, Fighting-, and Ground-type attacks, it actually has a   niche as an extremely bulky Curse user. Regirock has the highest Defense   in OU and very respectable Special Defense, especially with the boost   from sandstorm.(space this)Regirock's massive bulk can help negate its  bad typing and enables him it  to set up several Curses, Rest off any  damage, and bulldoze through  the opponent's team. Regirock also has   decent Attack and near-perfect  coverage with  just Earthquake and STAB Rock Slide. To top it off,  Regirock has a very  handy ability in Clear Body, which stops Intimidate  from reducing its  Attack.</p>
(stay consistent with your gender.)
<p>Despite these  useful assets, Regirock(space this)requires some team support to function. A Sand  Stream Pokemon is important and   a way to deal with your opponent’s  Water- and Grass-types is absolutely  mandatory. Regirock also has  pretty stiff competition with Tyranitar  for a team slot, as he it has  better Attack and Special Defense and even provides his its  own sandstorm.  Despite these somewhat disappointing setbacks, Curse  Regirock is still  very destructive if properly supported and  played.</p> 
[SET] 
name: CurseRock
move 1: Curse
move 2: Rock Slide
move 3: Rest
move 4: Earthquake / Sleep Talk
item:(space this)Chesto Berry / Leftovers
nature:(space this)Careful 
evs:(space this)252 HP / 4 Atk / 252 SpD
[SET COMMENTS] 
<p>The idea of this set is to come in on something a Pokemon who doesn’t  threaten Regirock, such as Heatran, Zapdos, and Weavile,  and start setting up. After a Curse or two, Regirock  will be able to  take even super effective physical attacks with over  half of its HP remaining. Should your  opponent’s special attackers be gone, he Regirock will become hard to stop have a hard time breaking  through Regirock.  When Regirock is running low on health, it can just  Rest off the  damage, wake up instantly thanks to Chesto Berry, and  attempt a  sweep.</p> 
<p>When using Regirock, it’s inevitable that  it will be compared to Tyranitar. However, Regirock has his its  advantages:  no 4x weakness to Fighting-type attacks, no weakness to  Bug-type  attacks, and superior Defense. This enables it to come out on  top  against Gyarados, Dragonite, Lucario and Scizor, all of whom  Tyranitar  loses to.</p>
(i think you can also mention clear body negating  gyarados's intimidate, allowing regirock to keep its curse boosts. you  can add this in at the end if you want: "Regirock also has Clear Body,  preventing Gyarados's Intimidate from hindering its Attack.")
[ADDITIONAL COMMENTS] 
<p>Stone Edge is an option over Rock Slide, as  the extra power is sometimes helpful at the cost of less PP. (period) however, the comparative lack of  PP is a big issue. In the last slot, Sleep Talk is an option, as it  allows Regirock to use Rest more than once (i  don't understand this. sleep talk won't pick rest to let regirock use  it more than once. perhaps reword this to whatever you meant? otherwise,  i would remove this part) and allows it to use  Leftovers instead of Chesto Berry. Running Stone Edge becomes more viable due to Sleep Talk consuming PP for Stone Edge This also makes it more viable for  Regirock to run Stone Edge; however, running Sleep Talk over Earthquake  gives Regirock a much harder time against Steel-types. The EVs can also be   tweaked by investing in either more Defense or Attack  should you want more physical bulk or attacking power, respectively; invest in  Defense or Attack, respectively.</p>
(avoiding use of "double" semi-colon in a row at the last two sentences.)
[Team Options]  
<p>When choosing a Sand Stream partner for Regirock(backspaced),  you should  always use Hippowdon, since  Tyranitar and Regirock share  so many  weaknesses. Because many of Regirock’s counters are  Water- and   Grass-types,(space this)specially defensive Zapdos is Regirock’s best partner  by far, as Zapdos can counter many of the aforementioned Pokemon and resists many of Regirock’s weaknesses. Regirock returns the favor by dealing with Blissey and Snorlax with  little problem. Magnezone is an exceptional partner as well, as it ensures that you can take down Bronzong and Skarmory. (period) however Sadly, (comma) Magnezone and Regirock share a couple of weaknesses: Fighting and Ground. The aforementioned Zapdos can counter Bronzong and Skarmory as well; however, he it does cannot trap them. Heal Bell Dragonite is also a good teammate; because he it allows Regirock to wake up after using Rest, should the need arise,  and can also take on most of Regirock's counters, bar Water-types.</p>
(toxic spikers such as tentacruel and roserade  could be helpful against water and grass pokemon not called tentacruel  and roserade themselves but those are rather uncommon anyways.)
[Optional Changes]   
<p>In OU, (comma) Regirock(backspaced) (removed comma) doesn’t have too many other options. Regirock  does have the highest Defense in OU and (shuckle lol) could run a somewhat effective  tank set due to its impressive physical bulk; however, its bad defensive typing and lack of reliable  recovery really hurt its usefulness as a wall tank. Regirock It could also attempt to  run a Rock Polish set similar to Agility Metagross, but it lacks the raw power  and Speed that enable Metagross to cause havoc and reach important benchmarks.</p>
 [Counters]
<p>As mentioned many times , Grass- and Water-types, such as Suicune, Celebi, and Breloom, are a real  pain for Regirock. In particular, Suicune, Celebi, and Breloom are the  most problematic.  Suicune and Celebi can set up on Regirock, while  Breloom not only  resists Earthquake and Rock Slide, but can freely set  up a Substitute,  put Regirock to sleep, or just and wear beat  it down with its  STAB attacks. Skarmory can phaze Regirock without too  much trouble, but  can do nothing else; in a one-on-one situation,  Regirock will always emerge  victorious.</p>
(add in trick users such as rotom-a and gengar and  encore users such as infernape and togekiss as counters. of course,  they must be wary of switching in blindly; they must make sure they're  not switching into a stone edge. bronzong is a pretty nice trick user  too.)
    
(also, i think taunt gliscor with toxic/earthquake counters this set nicely too.)
(AND, maybe hippowdon can tag along skarmory. its  earthquake only does around 25% to a +1 regirock though, so that's why  i'm thinking it can roar just like how skarm whirlwinds. also, hippo  resists rock so it's slightly better off.)