Inner Fire

Inner Fire is a common priest spell card, inducted into the Legacy set, formerly from the Classic set.

Strategy
This is a very strategic card. It can be used to improve minions whose Health is higher than their Attack, such as turning a 2/7 into a 7/7. Conversely, it can be used to weaken enemy minions whose Health is lower than their Attack, such as by turning a 7/2 into a 2/2.

This card works very well in combination with Divine Spirit and other Health-increasing effects like Power Word: Shield. Priests can use these effects to increase a minion's Health as much as possible before using Inner Fire to translate that improvement into Attack. Common minions with a lot of hit-points include Shieldbearer, Oasis Snapjaw, Mogu'shan Warden and Gurubashi Berserker.

Inner Fire is a key part of the Divine Spirit combo, allowing the massive increase in a minion's Health to be translated into Attack. Lightspawn effectively has a constant Inner Fire effect, allowing the priest to execute such a combo without playing this card.

Lore
Inner Fire was a priest ability in World of Warcraft that increased the priest's armor and spell power. Originally featuring charges that were depleted each time the priest was attacked, the spell was later turned into a non-depletable long-duration buff, before eventually being changed to last until cancelled. Since its beginnings the buff had been an automatic and mandatory buff, expected to be maintained at all times, and with its latter incarnation requiring almost zero player interaction, it was a perfect candidate for removal in Warlords of Draenor 's 'ability pruning'.

Trivia

 * Inner Fire was removed for selection in Arena on September 15, 2016 but was reinstated on December 9, 2018.
 * Inner Fire's flavor text references the infamous.
 * The artwork for this card comes from the World of Warcraft Trading Card Game "Fields of Honor" series, for the card Baelgond Soulgrace.

Patch changes

 * Moved from Classic to Legacy set.
 * Added, replacing Prayer of Fortitude. Change a minion's Attack to be equal to its Health. [3 mana, common]
 * Added, replacing Prayer of Fortitude. Change a minion's Attack to be equal to its Health. [3 mana, common]