As someone who had battled this team multiple times, I must say that this is an outstanding team. One thing that screwed you over was the fact that you don't have a rapid spinner. With volcarona and scyther both extremely weak to stealth rock, they both got ohko'd by one of my pokemon(specsmence, maybe?). I would suggest starmie, as your haxorus is incredibly dangerous but gets ohko'd by any dragon types. Starmie ohko's every mainstream dragon except for hydreigon, which it 2hko's. Run this set.
[email protected] Specs
-Rapid Spin (Starmie's purpose on your team)
-Ice Beam (dragon killer)
-Recover/Thunderbolt (Healing/Coverage) Just run thunderbolt.
128 HP / 252 Spatk / 128 Spd
Max spatk is necessary to kill. Choice Specs allows you to ohko hydreigon... Put life orb if you want to have flexibility.
On to the rest of your team. Volcarona needs an item... Put maybe a healing berry. Sitrus berry I think?
Togekiss... Bright powder for sure, but if it's banned, then go with a fighting gem.
Haxorus: This is hard... I'm assuming item clause is in effect so a gem of sorts. Ground gem is probably your best bet as this allows you to ohko ferrothorn after one, maybe two dragon dances.
Now, on to the getting rid of stage. We added starmie, so I would recommend getting rid of togekiss. Your other option is getting rid of lucario. Hope this helps and good luck battling!