CEW Part: Circle Survivor
Weight: 4.5g plus 0.23g Clip
Large bowl attached to EG shaft (thus semi-free spinning) and protecting the base of the Beyblade.
Top part of the Beyblade generally continues spinning after Circle Survivor itself topples, providing an unusual form of life after death, the inverse can also happen and circle survivor can keep the Beyblade teetering upright at very low RPM.
As it becomes the main contact point yet is not connected to the weight of the Beyblade, this makes it an incredible protective barrier.
Tip is quite close to Change shape, but sharper even than Customize Metal Change Base, so fairly immobile by itself, but more aggressive with use of the Engine Gear.
Sharpness wears down quickly, increasing aggression and lowering survival. The increased aggression does make it somewhat easier to KO, as much of Circle Survivor's defense comes from how hard it is to push far enough to get it out of the stadium - being closer to the edge reduces the distance required.
Free spinning protective bowl protects against low hits (especially right spin Upper Attack), greatly redces the ability of opponents to steal spin, helps disperse force of Smash Attacks which hit it, and its size and shape mean it often traps less stable opponents below itself.
Rim does allow it to be force smashed to an extent, allowing certain Weight Based Defense and Force Smash combos which can also outlast its LAD to win by OS.
Main weakness, though, is combinations which avoid it entirely by hitting the other parts of the Beyblade. This allows some combos to have very obscure bad match-ups against things like tall Flying Defense (Hasbro) combos.
While very powerful against less stable combinations which are easily caught under it and ground into the stadium, more stable Zombie and even Defensive Zombie combinations can outspin it.
Its unique properties result in an entire type based around it, Circle Survivor Defense being one of the most imposing types of modern competitive plastics - to the point that prior to the legalisation of Storm Grip Base tip inversion it had managed to wipe Traditional Upper Attack clean off the competitive landscape.
Also the heaviest CEW part and part of one of the heaviest SG/BB/Tip setups possible (with Right Engine Gear (Circle Defenser) and First Clutch Base (Zeus Version)), allowing for Circle Survivor/Weight Based Defense hybrid combinations and generally adding 'additional bulk' to the list of the parts strong defensive properties at the cost of some hit absorption.
Overall, a complete Defensive titan, and one of the most obscene and scariest parts of the generation being a total wall to a lot of Attack combinations and warping the Attack meta towards only the most brutal setups, a plastics equivalent of something like MFB's BD145. Circle Survivor is something that every Blader should be prepared to stare down at a tournament.