His back throw kills at higher percents. His down tilt is super fast if you need something that attacks similarly to the fan item to rack up damage of course. His up air is strong. You can set up a chain of forward airs or at least two in a row. His second jump is unique. PK Fire can trap opponents if you want to forward smash. Forward smash can also reflect certain projectiles if times right. I think the PSI Magnet can slow your fall a little bit so if you are an advanced Ness player that is recovering off stage that is an option up against certain characters. PK Flash can be a good KO move but hard to pull off (so I'd rather use up air unless stale). I've seen players use his up special a lot. Not necessarily to hit you but himself for KO and protection (like super armor I think). Ness' PK Thunder can mess up characters trying to recover, especially if you hit them into the stage. Oh and it might be nice to practice his dash attack so you can get the sweetspot on it, because it can be really strong.