to verity, to fulfill, to examine, to hold an inquest
騐 centers on careful inspection to confirm truth or completeness: verifying, examining, or holding an inquest. The idea of fulfilling a requirement extends naturally from verifying that something is complete.
騐 combines 馬 (horse) with 念 (thought, attention), likely suggesting careful inspection of horses or using horses in verification. The exact historical development is uncertain.
A horse (馬) under careful thought (念) is being examined and verified. Picture an inspector checking every detail of a horse to confirm it meets the standard.
For ケン, imagine Ken examining a horse: Ken -> ケン, and his careful inspection verifies everything.