Hydra Ichi is an A-rank support debuffer built around speed manipulation, and single-target pressure. That's it. That is why he is one of the few A characters used in competitive. Ichi has one work, and only one: be the first to move in battle and accelerate an ally.
At max available skill values, his kit has clear synergy. Skill 3 is the most practical part of his support identity, as it grants an ally a very large speed boost enabling a lot of combos and getting the first move in a battle. Hydra Ichi is a niche speed enabler, we can see him in Jamir, all PvP rankings, etc. Of course there are other units like Gemini Defteros, who can do the same, but with a lot of bans, Ichi is an interesting choice.