I’d like to see variant blood rage/seraph strike/slash, stacks2duration/bane/enhanced bloodbath and so on as a reward for ~4/12 endings. There’d need to be 12 per expansion if they do a v&c per raid tier, but would work as a method to let people have more variety in gameplay while not being in content that matters much.
The unlockable actions could be themed around the v&c they’re from but that might be unnecessarily restrictive - the most recent one would be difficult to incorporate into any non-arcanist job. Possibly any non scholar if lv90+ summoner has thrown the towel in on arcanima.