First, I stand corrected on the use of Dispel Magic to temporarily disenchant magic items.
Or, to be specific, item. Just reread the whole spell.
You can target an object or creature to try and take down spells currently in effect.
You can target an object to try and suppress it's magical abilities.
Targeting the creature doesn't suppress that creature's items though. To shut down his armor or weapon(s), you need to target each one separately. So in all likelihood, you'll get a shot at one item.
Make it his armor, or major defensive item. If you can't effectively hit or hurt him, he can take his time and beat you to death with a pencil stub
Second, while Dispel Magic isn't subject to Spell Resistance, damage spells like Shatter usually are. And yes, his SR applies to himself and to all of his attended items.
Look for spells like Lesser Acid Orb. Acid ignores Hardness of items it attacks, so it's a real effective way to ruin gear.
Regarding the Ranger: If I'm running the Death Knight and the Ranger is being a pain, I advance and try to Sunder his bow. Without the Improved Sunder feat this would provoke an Attack of Opportunity from him which would negate my Sunder. But he's armed with a ranged weapon, and ranged weapons can't be used for Attack of Opportunity. Unless he has a natural weapon or an Unarmed Strike ability, he's treated as unarmed. Even if he has a spiked gauntlet or some such, that wasn't the weapon he ws using, so he still doesn't get that AoO. And bows, being wood and only an few inches thck, break really easily. Alternately, Sunder that worn item called a Quiver. The bow is useless without arrows, and I'll bet the leather quiver breaks easier that his (probably magical) bow.
So, if I'm running anyone other than the Death Knight, I want to protect that Ranger and keep the Death Knight away from him, outide Sunder range.
Third, by the rules, skills like Diplomacy and Intimidate aren't contested rolls. They both have hard target numbers to achieve certain effects.
Of course, by the rules, you can't use either one on another PC. Silly idea that Players have free will... <grumble grumble grouse>
Unless he has some effective ranged attack though Air Walk is a near perfect defense. You go up, he stays down, giving you time to make sure he stays down. Throw it on your Ranger friend too and the Death Knight is done for, plain and simple.
If you really want to be the "good guy", use your token to pull a 5th level spell: Raise Dead. Then, after you've killed him, bring him back, fully alive and no longer a Death Knight. He was your character's friend and trusted companion for years, after all. (Warning, this might tick the other player off no end. But then, why else would you do it?
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