The Shaman Legendary Kalimos, Primal Lord allows you to choose between four different Invocation Options if you played an Elemental card the turn before playing this card.
The four options are:
Invocation of Fire
If you’re playing the SMOrc plan or threatening lethal you can choose to do 6 burn to your opponents face.
Invocation of Water
This is a good option for control Shaman decks or if you’re close to dying. 12 Health along with the body of Kalimos can help you stabilize.
Invocation of Earth
If you have a good read that your opponent can’t deal with a board of 1/1’s or you have a card to buff them this option can turn the game around.
Invocation of Air
3 damage to all enemy minions is a great anti-aggro tool along with playing the 7/7 Kalimos.
It’s the flexibility of having the choice between the four cards over some RNG that makes Kalimos so powerful.
You can set up a board swing turn, choose options to support a control archetype, or just use the burn as additional SMOrc.