Lately, I've noticed regadrless of the game and edition, my games pretty much flow as a Final Fantasy Game: Roll Initiatives, and spend the whole encounter being a piñata that hits the players back and remains static on the same spot.
The problem is that I have issues fleshing out the monster as another piece of the story and scenario, it's really difficult for me to do so. Many monsters have spells, multi attacks, cool abilities, and I end up only using the passives like "Geez, the monster is healed! It seems it absorbed your fire attack" and "You know that won't work, it's a ghost".
It becomes very boring. I read all the lore of the monsters I use and I create some cool ones for the ones I make, but in the end it just turns out being the same, I just feel I'm controlling a daage dealing machine and not a big bad monster; specially, some monsters have VERY dangerous abilities that can kill the PCs, and I'm ACTUALLY afraid of doing so, so I REALLY hold back and sometimes I even end the combat 3 round later, making it pointless.
How can I get inside the role of the monster and forget about everything else?