Rotation & Combat Flow
When playing for Savage Axe after charging your shield you absolutely want to overcharge your phials as that overcharge damage is going to be utilized for the next several minutes. Next we need to get into Savage Axe Mode, if at any point during the building phase you perfect guard and enter it through a counter attack that's great, but if that hasn't happened by the time you have overcharged phials and a shield infusion, you're either going to fish for a perfect guard to counter off, look to perform a mount on the monster assuming it's off cooldown, or attempt to cause a wound so you can rend to enter Savage Axe. The act of actually getting into Savage Axe can vary in the amount of time required, If you're sitting on overcharged phials for an awkwardly long period of time, attempting to cause a wound to rend with elemental discharges or SAEDs can be a good way to fill the gap. Wounds get harder to cause the longer the fight goes however, so you'll want to practice your perfect guard timing as a reliable method with no diminishing returns based on the duration of the fight.
Once you get into Savage Axe Mode, You'll want to spend as much time as possible shredding with Held elemental discharge 1 and 2, after your second discharge you can either continue the combo with a Standard Attack in Axe Mode which you can also choose to hold down then loop back to discharges, or if you have the opening begin spending your phials half of one at a time by activating AEDs after your discharge 2 with a further held heavy attack as well as the proceeding follow-up, as these will deal extremely high damage in exchange for that half a phial. Axe mode in general I find much more user friendly when played almost entirely in focus mode, as the attacks are quite slow and are typically better when aimed manually, this is especially the case with SAED.
Gear Selection
Bone Strongarm III keeps things simple providing straight forward additional damage with
Attack Boost and fantastic quality of life in the form of
Load Shells drastically cutting down on the amount of time it takes to build overcharge phials.
Burst Has virtually perfect uptime while utilizing Save Axe Mode with the Charge Blade providing a substantial increase to your damage potential.
Burst Boost I Ensures this while adding some extra free attack ontop.
Flayer Makes it easier to create weakpoints which let us easily get into Savage Axe by utilizing Double Rend. The additional sustain from
Decimator I also keeps us in the fight for longer thanks to the healing factor it provides us regularly throughout the fight, meaning we have to back off less often allowing us to continue taking advantage of our Savage Axe duration.
Weakness Exploit Furthers the advantage provided by the additional Weakpoints.
Decorations
I've left the decorations blank because in low rank you are not likely to have everything available nor should you be particularly worried about going out of your way to farm specific ones, as this build will blast you to HR30 without needing to worry about using specific decorations. Good recommendations however would be
Protection Jewel
Steadfast Jewel
Attack Jewel as well as elemental resistances when having a hard time with a particular monster.
Attack Boost Is just more raw damage, no stipulations, no gimmicks, just more damage all the time. Great to maximize the entire game for anyone especially newer players.
Divine Blessing Having some extra procs of damage resistance can be extremely helpful, especially while learning the bosses when you are likely to be hit the most often.
Stun Resistance Makes entry level High Rank Monsters more forgiving, Getting chain CC'd is something that can easily happen due to the increased chance High Ranks have to cause stuns with their higher damage, Making your gameplay experience more forgiving.