Urizane's Watermelon Alter
Bombs · Shields · Platforms · Teleportation · Watermelons
Urizane's Alter is never given a grand formal name. It does, however, let him use watermelons for an absurd range of functions including explosives, barriers, platforms and transportation.
Why it matters
s-CRY-ed never requires an Alter to look cool in the same way twice. Kazuma gets a rocket fist. Ryuho gets a lethal ribbon monster. Urizane gets watermelons. The setting accepts all three with a completely straight face.
Absolute Perception
SPOILER!
Elian · Electronic Observation / Information Control
Elian's Alter allows him to create and control electronic systems for observation and communication across enormous areas. In a show where most Alter users solve problems by hitting them, Absolute Perception turns information itself into the ability.
Why it matters
That makes Elian valuable to whoever controls the system around him. Under Mujo, surveillance becomes another layer of the fortress. Later, the same kind of reach can be used for something as harmlessly ridiculous as broadcasting Kazuma and Ryuho's final fight.
The Tokonatsu Sisters
SPOILER!
So Kigetsuki · Three Alter Puppets · Burning Summer
So Kigetsuki's Alter creates the three Tokonatsu Sisters, artificial women with their own limited abilities who can combine into the much larger Burning Summer form. They are less like equipment than a tiny cast of characters generated by one user's power.
Why it matters
The Tokonatsu Sisters are s-CRY-ed at maximum early-2000s confidence: specific, ridiculous and dangerous enough that nobody in the story needs to stop and ask why one man's psychic superpower manifested as three women who can combine into a monster.