So, with the new Willow coming up I was thinking about the potential tricks that could be done with her new-ish set of abilities. However since the information is pretty vague this is nothing more than speculation.
Currently a fun strategy (not really efficient right now but..) that utilizes Bernie is to use all the insanity inducing items alongside several Bernies to fight bosses. Nightmare armor, night sword, blue caps, bat bat, and some others. If Bernie is actually capable of fighting there are interesting possibilities of creating Bernie armies to fight bosses as well as more effectively using the "Go Nuts" items/weapons. My hope for Bernie's buff is that he will make it feasibly possible to fight bosses totally insane without an annoying amount of preparation beforehand effectively giving Willow easy access to insanity inducing items with little need to prepare for the penalty of being insane. Not to mention if Bernie is strong then being able to drop a bodyguard at will is also pretty interesting concept to play with.
Bernie also has the potential for being an EXTREMELY effective nightmare fuel farmer if Bernie is actually strong. Especially if there is a small army of Bernies. Equip a nightmare amulet, bone helmet, or just plain go insane and have Bernie knock them all out while you tend to other matters. IF Bernie is strong then Willow may have taken the slot for the most efficient nightmare fuel farmer. The only other two characters that have an innate ability to gather nightmare fuel faster are Wolfgang and Wigfrid since they can kill them easier and even then they have to dedicate their focus on farming fuel. (Maxwell/Wes don't count since it's easy to set up an insanity farm and they don't have any innate ability to kill them faster)
Another interesting possibility is that according to the teaser for reworked Willow Bernie can now be equipped for sanity and warmth. Unless JoeW actually meant insulation this means that Willow could have a portable personal heater allowing extremely easy winter travel on the surface as well as easier winter spelunking. If the player has the hindsight to use Bernie for heat in the Winter that means that it will be unnecessary to carry around fire making supplies freeing up a couple slots of inventory space and being oh so very convenient.
Here's hoping Bernie is actually strong. If Bernie ends up being really weak then I can't say i'm all too impressed with the rework since everything else is pretty meh for advanced players and she'll just be a new player oriented survivor.
TLDR; If Bernie is strong then Willow could potentially the best nightmare fuel farmer, efficient winter/summer explorer, and have easy access to insanity inducing items.
If anyone thinks of any more interesting possibilities with her new abilities please share. I'm definitely excited to play her because regardless of what people think she's definitely being buffed from her current state.