Shard
Shards are fragments of Entites that serve as the source of parahuman powers.
Overview
Trigger Events
Shards can "Ping" off of another Shard during the Host's Trigger Event - giving them some kind of additional ability.
If multiple people undergo a Trigger Event at the same time, it creates what is known as a "grab-bag cape". These capes are incredible rare and their powers, while different, are usually similar to the other Hosts and complimentary to each other. They are meant for the end-game of the Cycle, serving to stress-test powers/compare and contrast the smaller powers.
Second Trigger
The Shard draws from context and explores and/or conceptualizes new uses for its powers. The Shard begins splitting off to find a new, but similar Host - piggybacking off the original Shard's context and experience - but then a major event prompts to catalyze and consolidate in the current Host instead.
If it's in an adult before finding its way to the child, it can begin this splitting-off process (generally requiring time or a degree of stress to allow for the maturation).
Second Triggers are exceedingly rare, and generally do more harm than good.
Effects on Host
The effects that Shards have on their Hosts are dependent on several factors including but not limited to: age of the Host, the Host's personality, the Host's Trigger Event, how much the Host embraces the Shard's need for conflict and the Shard itself.