Hoy about a 'mon to switch in physical attacks? Like a steel type, Mega Mawile could take in fairy attacks as well as flying type (pikachu shouldn't), and still keep up the offensive with swords dance.
Plus, Mawile is considered Uber in most places so you won't get to use it in smogon or competitively outside of this forum.
Otherwise I'd recommend a flying type like Skarmory just to take hits and roost them up, on top of that you can use Whirlwind to screw up the jerks that spam self buffs. But that flying tank makes things too easy.