You should be able to go toe to toe with Pika......mostly......on the ground so you have to fight hard to get a upper hand here. The thing is that alot of Pika's airs have loads of priority or is muti-hit so if you know you won't be able to out space him in the air revert back to the ground. Some thing i have found very effective.....against almost all the cast....is the jumping PK fire it has not as much lag and it leaves you less vulnerable, and it hits alot. But really Try not to rush in play more defensively, use Yo-Yo blocks, retreating Fairs(I use tab jump), retreating PK fires, PK thunder....or PKT2, and when he is knocked off stage switch quickly to the hard offensive and try to take advantage or at least every time you knock Pika away try the PKT juggle just to build damage, and save Bthrow, and Bair, and Uair(even.........especially off stage) . But its really just practice, try the two LVL 9 Pika computers and then do them on one team, and then move to Wi-Fi and practice more.