That quagsire of yours is nothing original , ive come across it a few times and used it myself a few times. Just toxic it or trick it a scarf and hes dead meat for the rest of the match ( just like gastrodon). I really like playing with my favorites pokes and utilizing movesets/combos that arent common. An example of this core wich i had great succes with , consisting of tyranitar-weezing-cradily :
Ttar @ lum berry 252 hp/ 52 atk/176 spa / 28 spe
Nature : Quiet Ability : sandstream
Moves : Substitute / ice beam / dark pulse / focus punch
Old tboah used as a lead. Works great for bluffing SR and then set up a sub and pick your move of choice. Takes care of blissey ,chandelure , most gengar , deoxysleads,hydreigon ,latios/latias , starmie,and other tyranitar, ninetailes leads , if u want to take on toads replace a move with tbolt ( wich 2koes non specdef variants).
Weezing @ black sludge , 252 hp/ 252 def /4 spa
Nature : bold ability : levitate
Moves : fire blast , pain split ,will o wisp/toxic , stockpile
A physicall wall , and great in OU. Takes on excadrill all day long. Most fighters are screwed by status , and even if they carry guts weezing can simply utilze stockpile to keep up with the boosts and keep on walling until they die. Checks terrakion , physical vizirion , scizor , skarmory ( physical defensive is 2koed by fire blast) , landorus , hippodown ,breloom, physical ttars , haxrachi , conkulldurr , bronzong is 3koed by using wow and fire blast 2 times ( tough the burn is usually enough to make it useless , and burns dragonites while dnite needs +2 and life orb to ko weezing with outrage.
Cradily @ leftovers , 252 hp ,252 spdef , 4 def
Nature : careful Ability : suction cups
Moves : curse , rock slide , seed bomb, rest
This thing is simply amazing , it reaches 374 hp /516 spdef and 230 def in a sandstorm. She walls EVERY special attacker in OU , as even a timid 252spa/252speed volcarona needs +3 spa and life orb to ko with bug buzz. Meaning cradily can even switch in on the SECOND quiver dance and still ko with rock slide. Sets up on : Latios , latias , blissey , jellicent , skarmory ,ferrothorn , ferrothorn, magnezone, espeon , heatran ,ninetailes and toad if sand is up! , porygon2 ,starmie, thunderus , vaporeon ,whimsicott, gliscors without taunt , tentacruel , swampert , chandelure , gengar ( focus blast has CHANCE at a 3ko if it hits 3 times in a row , 252spa timid@lifeorb). Stopped cold by taunt or trick.However if taunted it can simply switch out and come back in , taking only 51 % from a specslatios's draco meteor (wich isnt even a 2ko with leftovers if he didnt had the stats drops. Rest is necesarry because when people see they dont do enough damage they will either toxic you , or try to whirlwind you out (wich will fail thanks to suction cups).
I got bored from this core , so i tought why not share it :).