Quickest way to move up a tier or two is give literally anything with an -ate ability extreme speed. Yes, even Gardevoir. But I fucking hate -ate abilities.
Things I would want:
Dratini/Dargonair/Dragonite with Coil
Articuno with Calm Mind
Buzzwole with Drain Punch (why doesn't it already get this?)
Kyurem with Ice Punch
Moves that don't exist that I want
Homing Fireball
Fire, special, 40BP, power doubles if foe switches or uses U-turn or volt-switch. Hits before the are able to switch (basically a Special Fire-type pursuit, give it a few fire-types)
Lightning Blade
Electric, Physical 90 BP, increased critical hit rate 95% acc
Give this to everything with blades (except muskedeers) and every physical electric type, and some of the non-physical electrics
Banshee Shriek
Ghost, special, 75 BP
Sound based, strikes at physical or special defense, whichever is lower
(give this to various ghost types with mouths, so yes to Froslass, but no to Aegislash because it has no mouth)