Comparative and Superlative of invisus

The title says it all. I can’t find them. Not in my main dictionary source (wiktionary), nor in L&S. Is it really invisor/invisore and invissimus, -a, -um? Or is it one of those adjectives that take magis and maxime for the comparative and superlative respectively? I’ll take anyone’s word here as to what the comparative and superlative may be for invisus, but if you can could you link the source you got it from?

Gratias vobis ago.

I’m editing this after I posted it to clarify as to which invisus I’m referring to, for apparently there are two. One means unseen; the other means hateful, which is the one I’m asking for here.

invīsiōr (you were missing the i between the s and the o) and invīsissimus are fine. As dictionaries do not list regular comparatives and superlatives, it’s little wonder you couldn’t find them.
Ammianus Marcellinus. Rerum Gestarum [ Amm. book 26 chapter 6 section 8 ] etc,

Pliny the Younger. Letters [ Plin. Ep. book 2 letter 20 section 2 ]

Thanks, bedwere.

So would the neuter of invisior be invisiore?

The neuter nominative would invisius. Invisiore would be ablative singular, all three genders.

Mehercule! You’re right, Barry. I was thinking that the positive of invisus was third declension so I was thinking that the neuter ended in -e. Much like gravis, grave. I need to slow down a little or else I’m like to make more mistakes like that.