About Eldritch Mods

can you get a BAD mod? as in one that actually hurts your build instead of buffing it?

and how many such implicits can you get? 3 suffix 3 prefix?

You can only have one implicit of each type.

You can look through the mods that have been datamined on poedb or look for a summary spreadsheet that has been posted on reddit to see if there is a mod that could end up hurting your build.

I have looked through them, but I do not remember every single one. So while there were some that I considered underwhelming, none come to mind that would directly harm a build, but that does not necessarily mean that there are none.