It's an anti-bruiser AP tank, I'm calling this one. It fits perfectly.
The Ductility and flexibility would give it the natural ability to soak damage.
The early mention of vocalization makes me think it will have some kind of shriek, be it a battle cry or otherwise.
A gap closer or some way to "stick" to enemies, as it is clearly goo.
Caustic attacks? Most champions out of Zaun have some type of corrosive aspect to them, be it armor or health.
Possibly one of the first ranged tanks? Flinging goo is a decent possibility, he could be a living siege tank.