After killing Theseus, Kratos obtained the key needed to unlock a door on the Steeds of Time. Behind this door was a small shrine to Cronos and when activated a hologram of the Titan appears. Via this hologram, Cronos, gives Kratos the last of his magic as the power of Cronos' Rage.
With this power, Kratos can create blue orbs of lightning to temporally electrocute and stun multiple enemies. One can then further level up this power to increase its damage. At level 3, the "cores" of the orbs explode at the end of the attack, which will then do further damage to nearby enemies and usually knock them back.
Cronos' Rage is one of the most effective ways to defeat or weaken a boss in this game, because usually the lightning orb won't let the boss or enemy move as long as it's being eletrocuted. Kratos can take advantage of this to escape from dangerous situations involving groups of enemies or even to attack them and harm them even more. The strongest bosses and enemies will resist to this effect and keep moving and attacking but will still be eletrocuted and harmed by the cores.
Since these were the last remnants of Cronos' magic, he was never seen using these electric powers again in the Series against any of his enemies.
Like Cronos, Zeus and Poseidon have used electric powers in the Series as well, probably because they are his sons. The only one of the Three Great Gods who has never used any kind of electricity was Hades, who relies on the power to absorb and summon souls against his foes. It is unknown if Hades has this kind of power in the Series or not, since he has never displayed it.
By acquiring the Urn of Poseidon and activating it in the Bonus Play or the Arena of the Fates of God of War II, Crono's Rage will be switched for Poseidon's Rage. It's also curious to note that both magics are very similar: both are dark blue electric powers that eletrocute all enemies close to Kratos at the same time. This supports the argument above about the sons of Cronos and their similar powers.
In God of War II, this magic is the best way to make big and even infinite combos. If it's used in the Arena of the Fates, for example, with infinite magic and enemies, Kratos is able to place as many cores and make as many combos as he wants for indefinite time.