It seems that good bowsers like to camp up in the air, funnily enough, by airdodging and koopa hopping until you run into it or he sees an opening. If you can see an opening where you can rush under him and usmash or upb, take full advantage. His upb out of sheild is deadly, so don't rush into his sheild. Expect him to space very well -- he's very large and hard to avoid when he's close. Nair is good for getting him away from you if he gets you in the air. If you get a chance to combo him, go for it -- otherwise, keep your distance with side and neutral b. Be careful of his down b -- punish it before it punishes you. Abuse dsmash for all it's worth, your down b is good for getting around him in a pinch for mixing up your defense. Punish his laggy moves with grabs -- but don't whiff for the love of cake.
I just fought the campiest arrow spammiest Pit I've ever played in all my brawl experience. All he did was roll to the edges of the stage, as far away from me as he could get and force me to approach through his arrows. As soon as I got close, he would either attempt to escape by rolling or roll around me trying to get an fsmash or grab in.
Powershielding as you walk is your friend. Short hop over his straight arrows, short hop air dodge to landed shield also works as an approach. When you're close enough, time a SH neutral b to intercept his arrow and shield grab him. You might be able to work in a neutral b to dash grab depending on how hard he's mashing b. Be patient and rack up damage with grabs, upb, tilts, and dash -> utilt combos. As soon as he reaches 100% start spacing side b tippers as you dodge. Fair's second hit will trade hits with his fsmash if you see an opportunity. As soon as he's a stock down, keep your advantage. He can't kill you with arrows, so let him rack up damage while you camp him back with b and side b until he's at critical% for an aerial or fsmash kill.
