Deino learnset and stats for reference
Deino currently sucks in LC, so I guess I'll just post a random moveset and get this question off the unanswered list. If you're reading this answer because you're really considering using Deino, then use Pawniard instead.
Deino @ choice scarf
EVs: 20 HP / 236 Atk / 36 SpD / 212 Spe
- zen headbutt
Outrage is its best STAB attack, and the other 3 moves cover stuff. The ability, item, and EV spread maximize physical attack and speed.