Runaway Echoes: Skill Tree & Sixfold Synergy — NTE

How Simulation Drill's six stages, the Skill Tree's Sixfold Synergy nodes, and an open-ended Saga of Infinity run fit together in NTE's Runaway Echoes event.

Last updated: September 9, 2026

Overview

Runaway Echoes runs from September 9 to September 30, 2026, 05:59 (UTC+8). It’s a survival mode on the Rails of Delusion: clear waves of enemies for the EXP orbs they drop, and pick a new ability card at every level-up along the way.

Simulation Drill

Simulation Drill gates the event’s endless mode behind six stages, each clearing by defeating a boss and moving to the next. By Drill VI the objective is to defeat 6 Echo Bosses within 420 seconds, and the attempt fails outright if the timer runs out or your character’s HP reaches 0.

Card Picks

Every level-up inside a run offers a choice of 3 cards. A Skill Upgrade raises one skill’s level and adds a stat bonus; a Relic Effect changes how a skill behaves instead — extra uses, reduced cost, and similar modifiers. Each card also carries its own rarity, and a higher one hands out a stronger bonus on the same skill: an Epic Meteorfall upgrade added 6.40% Crit Rate in one offer, a Legendary one on the same skill added 16.00% Crit DMG.

A level-up offer: two Skill Upgrade cards and a third on the same skill at a higher rarity.

Cards can be locked to keep seeing them or refreshed for a new set of three, both spent from a separate Skill Points balance built up over the run.

Saga of Infinity Mode

Saga of Infinity has no fixed victory condition — the character survives against endless waves for as long as it can, and the mode tracks the longest run as a personal best. Quest objectives track survival time in thresholds up to 1,500 seconds, and separately track Echo Boss kills across a match.

Saga of Infinity quests: survive for 300s, 600s and 1,500s, and defeat 30 Echo Bosses in a match.

Ending a run pays Talent Points for the Skill Tree, and the results screen breaks down every skill used by DPS, total damage, and uptime. One run that survived 16:41 and racked up 2,408 kills read like this:

Skill	DPS	Total damage	Uptime
Meteorfall	225,644.78	193,142,016.00	855.96s
Shockburst	160,751.17	113,583,728.00	706.58s
Shadow Slash	139,650.00	129,527,696.00	927.52s
Starburst Volley	29,347.42	29,320,592.00	999.09s

Saga of Infinity in progress: an AoE cast tears through a cluster of enemies.

Circling around an Echo Boss keeps its attacks from connecting.

The Skill Tree and Sixfold Synergy

Talent Points from Saga of Infinity runs unlock nodes on the Skill Tree, grouped into branches by element.

The Skill Tree: element-colored branches, each node costing Talent Points.

Node cost climbs fast deeper into a branch — Cosmos Empowerment IV alone costs 1,000 Talent Points, and its effect only applies “while Sixfold Cosmos is active,” tying the tree’s strongest nodes to the loadout requirement above: 6 equipped skills of one element (Cosmos, Anima and Lakshana are the ones the quest log confirms).

Cosmos Empowerment IV: +30% Universal DMG while Sixfold Cosmos is active, for 1,000 Talent Points.

A skill’s own tooltip states its element and ratio class directly, which is what decides whether it counts toward a Sixfold combo and how it scales. Meteorfall — the top performer in the run above — reads Cosmos / High Ratio / Meteor, with a 213.33% Skill Ratio against up to 3 targets on a 1.10s cooldown.