Overwatch · High Tier
No rationale is given for these changes. Per the document's stated policy, an unexplained change means the hero should simply be toned down slightly.
For each hero in S and A tier, slightly nerf each part of the kit. The author notes these are not all meant to be implemented, and invites feedback on which should take priority.
Each entry lists the move or ability affected, the adjustment itself, and — where the analysis states one — the problem it is meant to solve and the reasoning behind it.
Kiriko is one of Overwatch's entries — the full tier-by-tier breakdown covers the whole roster.