Catalyst of Aeons

Catalyst of Aeons is the sustain component for mana mages in League of Legends: 300 Health and 375 Mana for 1,300 gold in patch 26.21, plus Eternity, a passive that refunds 10% of the damage champions deal to you as Mana and heals you for 25% of the Mana you spend on abilities. It is two Ruby Crystals and a Sapphire Crystal with a 200 gold combine fee, and Rod of Ages is the only item it builds into.

What does Catalyst of Aeons do?

It keeps a mage in lane. The stats are plain, 300 Health so you survive a trade and 375 Mana so you have something to cast with, and Eternity turns those two pools into a loop.

Take damage from a champion and 10% of it comes back as Mana. Spend Mana on a spell and 25% of it comes back as Health. Neither number sounds like much, and honestly on a single trade neither is, but a mid lane mage casts hundreds of times over a game and gets poked for thousands of damage, so the loop adds up to a potion’s worth of healing every few minutes without a trip to base. Who benefits most? Champions with cheap spells on short cooldowns, since the heal keys off Mana spent, and champions who get hit a lot, since the refund keys off damage taken. In practice that is a Ryze, a Kassadin, an Anivia or a Cassiopeia (not a Zoe, who spends her time avoiding hits and casts one big spell at a time).

Is Catalyst of Aeons gold efficient?

Close but not quite: 90%. By the reference prices of 2.67 gold per point of Health and 1 gold per point of Mana, the stats are worth 1,175 gold against the 1,300 gold you pay.

So the 200 gold combine fee, and a little more, is the cost of Eternity. That is a fair trade for a mage who stays in lane two extra minutes per back, and a bad one for a champion who was going to recall anyway. Thing is, the passive’s value is invisible in the shop and very visible at twelve minutes, when the Catalyst mage is still farming at full Health and Mana and the opponent is walking back from the fountain. The sell price is 910 gold, which matters only if a game goes so badly that you need to sell a component, and that is rare.

What does it build from and into?

Two Ruby Crystals at 400 gold each and one Sapphire Crystal at 300 gold, plus the 200 gold to combine. The Sapphire first is the usual order on a first back, because the Mana is the stat a mage runs out of before level six, with the Rubies following on the next recall or two.

One item uses it: Rod of Ages, which keeps the Health and Mana and adds Ability Power and a stacking passive that grows over the first few minutes after purchase. Sure, that means the Catalyst is really the first half of a Rod of Ages, and nobody buys it without meaning to finish the Rod. The LoL items database lists the finished item’s current price if you want to see how far the Catalyst gets you.

Who buys it?

Scaling mana mages who plan to sit on Rod of Ages: Ryze, Kassadin, Anivia, Cassiopeia, Swain, Vladimir’s manaless kit excluded, Singed on some builds, and AP bruisers such as Mordekaiser’s mana-free cousins who want the Health rather than the Mana. Mid lane is the main home, with top lane mages a close second (a Kassadin top or a Ryze top build it exactly as they would mid). Who skips it? Assassins and burst mages who want damage on the first item, and any champion without a mana bar, for whom the Mana and half of Eternity do nothing.

How has Catalyst of Aeons changed over the patches?

Five entries since it entered the data in patch 12.22, most of them trading Health against price:

• Patch 13.1: Effect text changed.
• Patch 13.7: Cost 1100 → 1,300 gold, Health 225 → 300.
• Patch 14.1: Health 300 → 350.
• Patch 25.07: Mana 300 → 375, effect text changed.
• Patch 25.21: Health 350 → 300.

Put simply, the item got more expensive and tankier in 2023, then gave back the extra Health in late 2025 after a Mana buff earlier that year. For what it’s worth, the 25.07 change is the one worth remembering, because it moved the Catalyst’s identity a step away from Health and toward Mana, which suits the Rod of Ages mages who were buying it anyway. The full table above has every line from Riot’s data.

When should you buy it?

On the first or second back of a Rod of Ages game, ideally finishing it before level nine so that Eternity has the whole mid game to pay for itself. Rushing the Rod straight after is normal, since the Rod’s stacking passive rewards an early purchase. Not certain your champion is a Rod of Ages mage at all? The guide to LoL roles covers which mid and top lane styles scale into the late game, and those are the ones that start with Catalyst of Aeons.

FAQ

How much does Catalyst of Aeons cost?

1,300 gold in patch 26.21, with a 200 gold combine cost on top of its components. It sells for 910 gold.

What stats does it give?

300 Health and 375 Mana, plus the Eternity passive.

How does Eternity work?

10% of the damage you take from champions is restored as Mana, and casting an ability heals you for 25% of the Mana spent.

Does Eternity work on manaless champions?

Only partly. Champions without Mana cannot use the refund or the heal from Mana spent, so the passive does almost nothing for them.

What does it build from?

Two Ruby Crystals and one Sapphire Crystal.

What does it build into?

Rod of Ages only.