If you're not ready for it, Animate Objects does an incredible amount of damage for its level. It's counterable, but if you don't have the counter, just be ready for tougher monsters to get wrecked.
Wall of Force is pretty much like you said. If you have combined forces in an enclosed area, prepare for them to get cut into 2 smaller groups.
Magic Jar is a one-shot save or die on a weakened enemy, and you can do some serious shenanigans while controlling an important NPC. Not terribly bad unless the players to cheese it with some combination of death ward, clone, simulacrum, etc.
Sumulacrum is ripe for abuse with cheesy shenanigans. But even at its least cheesy, it's 1500 gp and a day of downtime to give yourself a buff of double your spell slots and two castings a round, which is pretty darn good for a 13th level caster.