Zelda receives help from her companion named Tri, which causes confusion as it is the same name as their gender, as the latter is a type that has not been captured by Null in the “Stable World”. Although it is not explained how Null was able to achieve this, it hints that Null was able at some point since the creation of Hyrule to study Tris and manipulate them, preventing them from fixing the rifts in Hyrule, also copying their abilities.
Zelda is given a tool called Tri Rod by Tri as her main tool for solving puzzles and assisting in combat. The main ability of this tool is to create Echoes, which are copies of objects or creatures to help her. This ability granted to Zelda by Tri also appears to be exploited by Null several times during the events of Echoes of Wisdom.
Through his rifts, Null can create dark copies of enemies to attack Zelda, and more deviously, he can create intelligent copies of non-playable characters (NPCs) to work for him and sabotage efforts to prevent the spread of the rifts. These dark copies appear to be extensions of Null’s consciousness, with the best example being his final version of Zelda, where Null absorbs the punishments that Zelda received from the gods, while possessing Null’s full mind and spirit.
Although this is not explicitly explained, Null’s ability to mimic Tris’ abilities is what enabled him to start spreading rifts around Hyrule, and also capturing Tris to prevent them from fixing these rifts. During the period when Null was imprisoned under Hyrule, he seems to have learned Tris’ abilities, copied them, and used them against them.
This theory gains strength in the form of Null’s final form, which clearly appears as a corrupt version of dark Tris. In different stages of Zelda’s final battle against Null, he also shows his ability to summon Echoes to assist in combat, similar to Zelda’s ability.
