What would you suggest against a Toon Link?
A good Toon Link is a tough match up for anyone, but especially Ness. Remember that his dair has outrageous priority and will go straight through both your yoyo and your utilt. Don't bother trying to preempt it as it comes down, just get out of the way and punish the lag if you can. Along the same lines, TL's usmash and uair usually both beat Ness's dair, so don't try it on the way down unless you're absolutely sure you can land it for a spike.
In fact, minimize your airtime altogether. If you're going to approach, always short hop. You can usually force your way towards TL with short hopped fairs. If he starts spamming arrows, bat them back at his face to get him thinking twice about doing that. Catch or powershield bombs. If you can get him to forsake his projectile game and get desperate, you can easily win the match. If you're lucky he'll try to dash in and hit you with a dash attack. Just shield this and grab him. Your back throw will kill a TL at 100-110%, so save that power.
All of Ness's specials carry lag that will destroy you against TL's speed, so don't go whiffing a PK attack or you can count on being fsmashed right the **** out. Be really cautious with PKT2. Once in a blue moon, you'll be able to bait a TL into approaching when they shouldn't and getting a face full of electrified Ness. But don't try this unless you're a stock up, because 90% of the time TL can rush over and put you at the mercy of his aerials (or worse) before you can curve the bolt around. The positive side is that, if you connect, you'll kill him with it even in the high double-digit percents.