Why HSbF6 , CF3SO3H superacid

HSbF6 is not a "real" compound; it's readily formed by mixing equimolar of SbF5 and HF.
upon mixing, the fluoride in HF coordinates with the SbF5, forming a stable (and non-cooridnating) SbF6(-) anion, and has a low tendency to form bond with the proton left.
Thus, it's said that the proton is left being "naked", attacking other materials readily.

(of course the proton isn't "freely traveling on its own" in reality, but let's don't make it too complicated here)


CF3SO3H is a sulphonic acid.
When the proton leaves the sulphonate group, the negative charge is readily dispersed through resonance via the two S=O bonds.
Moreover, the F atoms are highly electronegative, such that the F3C- group is strongly electron-withdrawing. This further helps to delocalize the formal negative charge on the oxygen atom.