How do element obstacles work in Egg Heist?

A team built around one element will meet sanctum routes it simply cannot open.

There are two kinds of obstacle. Some only need a skill: rocks in the dungeon break when you hit them with one, so any team can clear them. Others want a particular element. Some barriers only give way to a fire-type attack, and some sanctum mechanisms react to specific elements rather than to skills in general.

That turns your lineup into part of your route. The main job in the Lost Sanctum is finding the egg and collecting loot along the way. Every element you cover opens more of the dungeon for both. Bring a fire attacker and the fire barriers stop being dead ends. On higher ranks and difficulties the labyrinth sits under fog of war until you explore it, so you won't see what a route demands until you reach it. A spread of elements is safer there than a team built for one.