Eternals

Eternals is an upcoming premium champion mastery system in League of Legends.

Overview
In its simplest terms, you will have to pay per champion whose lifetime kills you wish to track - with 'lifetime' starting from the point of purchase. Your mastery flare is upgraded upon accumulating a certain number of kills, but there's milestones along the way to 'break up' the grind.

Unlike the freely available Champion Mastery system that broadly tracks your total playtime with a specific champion, Eternals track specific feats on those champions starting from the point of purchase - such as accumulated takedowns or gold earned.

Eternals are split into Sets that are purchasable on a per-champion basis, with additional Sets announced for the future. Progress toward Eternals can be tracked within the client within your Champion Collection, as well as in-game as an alternative tab that occupies the same location as stats and runes. Progress toward a milestone as well as completion of a milestone is broadcast in the kill-feed.

There is some sort of prestige system, branded as 'Rekindling', with a corresponding 'Personal Best', but the specifics are not clear at this time. The basic premise appears to be that once you reach the fifth milestone, you can reset your progress and receive a Personal Best. However, further milestones do not use the same scale as the initial five - making it unclear how the second completion compares to the first and current 'Personal Best'. Riot exclaimed that simply tracking your literal personal best wasn't ideal because '[they] didn't want everyone to hit their Personal Best in their first game', which seems to completely miss the point of a Personal Best system - since your first game will implicitly be your first score.

As originally announced, Sets would include 1 Unique Eternal and 2 Common Eternals for. As of the August 23rd announcement, Common and Unique Eternals will be split into separate purchases. Common Sets will be available in-store for, or during the Essence Emporium, and track broadly-applicable Eternals such as Kills, Objectives Destroyed and Gold Earned. Unique Sets are available in-store for and track progress toward three champion-specific Eternals.

Completing Eternals upgrades your Champion Mastery flare. It is unknown what happens if you have not yet unlocked Mastery Level 4, nor what happens if you 'Rekindle' your Eternal progress. It is similarly unknown if rewards are distributed on a per-set or per-champion basis, but players will receive their first flare upgrade upon getting an Eternal to milestone 5 three times or upon getting each Eternal within a set to milestone 5.

Each individual Eternal has a corresponding 'type' that roughly correlate to champion classes, which function to cosmetically segregate the achievements. For example, Eternals relating to crowd control score are classifed as 'Warden' Eternals, with a corresponding 'Warden' statue and blue visual flares.

Unique
For example,
 * Barrel Blast - Hit enemies with the third barrel in a chain. (The Empress)
 * Barrel Blast - Hit enemies with the third barrel in a chain. (The Empress)

Common
For example,
 * Gold Earned
 * Kills

Types

 * The Warden - Crowd Control - "You play on MY terms."
 * The Protector - Damage Mitigation - "Not today."
 * The Empress - Well Executed - "Big brains. Big plays."
 * The Guide - Enable Teammates - "TAKE THE LANTERN!"
 * The Warrior - Damage - "Rekt."
 * The Trickster - Deceptive - "/all ?"