Ok so far we've got...

zangetsu -> a 'cool' man wearing cloak and tainted glasses

zabimaru -> a baboon with a snake for its tail

and that's about all folks!

Now let's see, we've got 13 captains minus 1 (kenpachi), plus urahara, yoruichi, isshin and probably some of the other lieutenants who are close to achieving bankai (i believe we have no idea who they are) and people like ikkaku who have out of nowhere achieved bankai...

So whose soul cutter's materialisation would you like to see? and what would you like to see?

Imagining....... kuchiki byakuya's soul cutter....... a sakura tree??? O_o