Thunder Boost

Thunder Boost (サンダーアップ) is an ability that appears in Kingdom Hearts: Chain of Memories, Kingdom Hearts II, and Kingdom Hearts Birth by Sleep. It increases the damage done by Thunder-based attacks. In Kingdom Hearts: Chain of Memories, "Thunder Boost" is activated by the Yellow Opera card, costs 20 CP to add to your deck, and lasts for 1 reload, while in Kingdom Hearts II, it requires 5 AP to equip, and in Kingdom Hearts Birth by Sleep, up to three copies of it can be equipped.

Kingdom Hearts: Chain of Memories and Kingdom Hearts Re:Chain of Memories

 * The Yellow Opera card has "Thunder Boost" as its ability.

Kingdom Hearts II

 * Sora learns Thunder Boost at level 41 with the Dream Rod, 53 with the Dream Sword, and 99 with the Dream Shield.
 * Donald learns Thunder Boost after freezing the computers at the Dataspace.
 * Jack Skellington has Thunder Boost as a default ability.
 * Tron learns Thunder Boost after downloading the MCP-killer program
 * The Photon Debugger has Thunder Boost as its Equipment Ability.

Kingdom Hearts II Final Mix

 * Sora learns Thunder Boost at level 41 with the Dream Rod, 53 with the Dream Sword, and 99 with the Dream Shield.
 * Donald learns Thunder Boost after freezing the computers at the Dataspace.
 * Jack Skellington has Thunder Boost as a default ability.
 * Tron learns Thunder Boost after downloading the MCP-killer program
 * The Photon Debugger has Thunder Boost as its Equipment Ability.
 * The Meteor Staff has Thunder Boost as its Equipment Ability.
 * The Shock Charm+ has Thunder Boost as its Equipment Ability.

Kingdom Hearts Birth by Sleep
Thunder Boost can be attached to a or  Command recipe through Command Melding, either randomly or by applying a Shimmering Crystal.