Cygnus Hyoga is a classic control unit built around Ice Seal stacking and freeze conversion. At max skill, his kit applies seals very reliably: Frigid Punch gives 2 stacks, Restrictive Ice Crystal can bounce 3 times with an 80% seal chance, and Cold Breath adds another 80% application chance on attacks. Once enemies reach 3 stacks, Diamond Dust detonates and freezes them.
He is still useful for beginner control teams and can punish low-resistance enemies in PvE or early PvP brackets. The main issue is consistency against modern teams with better cleanse, immunity, or speed control tools. He is no longer a top-tier controller, but remains a practical entry option for players learning freeze-based tempo play. If you see him, he may be with the freeze team.