Rinblade Moddable?

Is the rinblade given in pre searing with +5 armor vs char, moddible with a suffix, or does the +5 count as suffix?

Could i put a +20hp sword pommel on it?

The +5 counts as the suffix, but it could, theoretically, be overwritten. I know next to nothing about Pre Searing drops though.

To actually answer your question, yes you can add another mod to it without the +5 armor vs charr being removed.

Try it. A preview window will open up showing the new stats on your weapon before the mod is actually applied. If you don't like it, just press cancel.