Frenzy used to double your attacks instead of adding one. A hydra sword turned every hit into d6 hits. So for a couple of points a Khorne lord could potentially dish out 60 strength 5 hits and still have points left over for other items (warhammer Online gold).
The crown of command gave characters an unmodifiable leadership of 10, even for breaktests. The cloak of mist and shadows would make said character ethereal or a runeshield gave him immunity from magic weapons Basic beastmen were toughness 4, 2 wounds each and quite cheap, so for a couple of points you could make a big beastmen unit as a bodyguard for your sorcerer that was nearly impossible to destroy by any means.
As mentioned before, frenzy doubles your attacks. A unit of basic chaos warriors with extra handweapons and the banner of rage clocked in at 5 attacks per model. There were lots of little nasty items that could instantly and permanently remove or kill a model in Warhammer. Like the black gem of gnar. Of the top of my head, you do a challenge, on a 4+ both models disappear from the battle.
Bufos hexscroll turns a single model into a frog with a stat line of all 1s. Sounds fun, where it gets really fun is that flying models were allowed to go flying high. If two opposing models went flying high they could fight each other, use bufos hexscroll to turn the other guys flying mount into a toad and they both go splat as they fall down to earth. If you have no time for your character, you can buy warhammer gold service from our site.