In terms of what, exactly?

Infernal Melody is a new attack in Rise. It’s just the flourish attack from World, but it needs a full gauge to activate, which fills with attacks from the horn.

Just tested in training grounds using left/right/left swing combos. It takes 34 hits to fill the gauge without Focus and 34 hits with Focus lvl 2. So apparently it isn’t effected.

Sry i meant hub 6* my bad^^

no, Hail Cutter is your best bet there, it cools your wyverns fire gauge down by half when used and gives you a full reload, but focus affects how quickly your charged shots fire, that includes the shots that turn you into A FECKIN VALSTRAX, though charged shots are absolutely garbage in this game on their own, its best used to pull off a fast wyvern stake or wyvern shot after a successful charged shot, but the damage of a charged shot on any and all shot types isnt worth throwing points into focus.

it does...it increases the rate at which the weapon charges its sword gauge so you can apply phial damage to your attacks, its best used on power phial switch axes, but honestly its much more effective to have 2-3 levels of enhancer and just pull off a single Elemental Burst Counter, but if you dont have access to the counter and you are in early game then throw a couple of points of focus on your build, but ONLY for power phial, the benefit of elemental phial, in addition to its elemental damage, is that its WAY easier to charge your sword gauge and get phial damage on your swings, power phial is the slowest at charging its phials. You can also do the 2-stage morph slash combo while in axe mode, the double swing attack in the axe mode at the end of the combo will fill about a third of your meter, if you have level 3 focus and have the double downward axe chop buff active youll pretty much get half your gauge from a single swing of 2-stage.