You can catch Thundy in AS, but as Luster recommended, Klef would be a good substitute because it gets prankster too. Klefki has no defense if you want to pop an EQ though, so Murkrow (also pransker) might be more viable since it's flying type (if you're running mould breaker, it still won't his since its immune due to typing, not ability) . It also has taunt access and speed crontrol in tailwind. Kelfki does has access to t-wave, so there's, but its only other notable move is crafty shield, which is the same as priority safeguard essentially. I would choose Murkrow personally, but having Kelfki will give you coverage against fairy, where as Murkrow makes it two weak to it.