Battery increases the power of special moves of allies by 30%. While it doesn't directly raise the stat, it still affects special moves.
Berserk raises Special Attack when the Pokemon with the Ability drops below 50% HP.
Beast Boost can raise the user's Special Attack if said stat is the Pokemon's most proficient.
When a Pokemon with Competitive has a stat lowered, its Special Attack is increased by two stages.
Download, if played correctly, will give a boost to Special Attack.
Flare Boost boosts the power of the user's special moves by 50%, but not the stat itself.
The Abilities Grim Neigh and As One (Spectrier) both raise Special Attack upon KOing a Pokemon, be it ally or foe. It's essentially a special version of Moxie.
Hadron Engine raises the Pokemon's Special Attack by about 33% while Electric terrain is active.
Lightning Rod raises the user's Special Attack if it is hit with an Electric move.
Moody has the chance to raise Special Attack at the end of every turn.
Solar Power ups Special Attack while in harsh sunlight.
Soul-Heart raises the user's Special Attack every time a Pokemon faints.
Storm Drain raises the user's Special Attack if it is hit with a Water move.