>>17284415You can go either way and be useful.
special side of things gets flash cannon and vacuum wave
physical gets close combat, bullet punch, crunch etc.
by focusing on either physical or special it allows you to get a nasty plot or swords dance off when you predict a switch then go for a sweep. I haven't seen mixed used before but that's not to say it's impossible. It might catch somebody offguard.
But with the lower power of those priority moves and extreme speed not being STAB you will have trouble dealing the damage to bulkier opponents.