Hex Reverse Fusion — Fusing Cards Into Stronger S-Rank Cards

Hex Reverse fusion is the base-phase system that combines cards into stronger ones, and it is one of the two documented ways to reach an S-rank card. The Steam store description lists fusing cards next to deck building, buying and selling and equipment upgrades, and the achievement list attaches three goals to it, which is enough to say what fusion is for even though the recipes are unpublished. This page covers the confirmed parts and marks the rest as unknown.

What Fusion Does Between Runs

Fusion belongs to the base you return to after a run ends, in the same block of activities as buying and selling cards and upgrading equipment. The stated purpose is to strengthen your collection and improve your setup before the next expedition, and equipment upgrades are described as the permanent-progression layer, so fusion is the card-side equivalent of that. Cards you fuse come out stronger, but the store page never explains what stronger means in numbers.

S-Rank Cards Through Fusion

Rarity is documented only through the achievement list, and only at the top end. One goal is earned by obtaining an S-rank card through fusion, and a separate goal covers pulling one from a random pack, so S-rank is the highest tier the official material names.

Documented	Not documented yet
S-rank cards exist	The full rarity ladder and its names
Fusion can produce an S-rank card	Which cards fuse into which result
Random packs can contain an S-rank card	Drop rates and pack contents
Fusion is repeatable between runs	Any cost, currency or card count per fuse

The honest reading of that table is that fusion is confirmed and its ceiling is confirmed, while every number in between is missing. Anything quoting a fusion success rate or a required ingredient list is not drawing on the official material.

What the Fusion Achievements Track

The three fusion goals are the closest thing to a fusion guide the game publishes, because they sketch how the system is meant to be used over time.

• Fuse a card: the first attempt, which confirms fusion as a mechanic you will meet early.
• Fuse cards 10 times: repetition, which confirms fusion is a routine base activity rather than a single event.
• Obtain an S-rank card through fusion: the payoff, which confirms the system can reach the top rarity.

Because the mechanics behind those goals are unpublished, the practical advice is to open the fusion screen at your base and read its own text rather than trusting a recipe from outside. The cards page explains what a card carries and the bazaar page covers the other way to gain cards, while random packs are the alternative route to an S-rank pull.