WILD HEARTS

Not really a guide but important info, as of now it only counts if you are the host of each monster hunt. The quest will let you join other peoples no problem but the achieve only tracks if you are the host or solo each monster. Super frustrating but can confirm.

Start with the Goldshard one since its the only deeply volatile that isnt weak to fire.

Use your weapon type of choice, the upgrade right before the grimstalker fire element one since that one is my pick for the other three and its not effective on goldshard. Have a talisman or armor piece with the resurrection skill, this is basically a free life. Put down all the celestial thread shines you can scattered in the arenas. There is no need to limit break your weapon but your armor should have some level of it. ( I just did the flat defense +3)

Now the big part. USE THE CELESTIAL SHIELD fusion karakuri. It was never in my build before but it is a huge game changer with only one life and going solo. It is the weakest as a wall but it gives you a shield that absorbs one attack and stuns the kemono when you get hit. I was shielded for a large portion of fight and if your threads are running low, use a shrine.

If your ever in danger just run away, you can't be followed and can use the break to get more threads and heals. Your life is more important than time. All the deeply volatile fights took me a little under ten minutes so time is rarely a factor.

For food I always choose meats. Smoked Dried red meat for attack % with some Smoked spicy meat for fire attack% I found defensive boosting food useless because the additional attack outweighs the benefit of low defense %

Now on the the fights.
All deeply volatiles are more aggressive, faster, do more damage, and have more health.

Goldshard
Its a pretty standard goldshard move set but faster. Its ranged attacks are fairly easy to avoid and its melees are mostly a form of charge. The only real difference I noticed is when it get away from you to do the spinning charge it come out REALLY fast, just make a basic wall as soon as you notice it spinning up.

Now upgrade your weapon to the highest tier fire element weapon. Limit break if you want but i found it unnecessary.

Ragetail
Its also a standard move set but with one addition, a lunge with the tail followed by a top like tail spin attack. It really likes this move so learn how to avoid and attack around it. There are a little amount of weakspots and destruction available so the head will be the go to attack location.

Deathstalker
The biggest change here is after it rages it gets a fast top like attack. It will spin around most the arena at random. The tell is a leap and hover in the air. Celestial shields are the best choice here for a stun, but if its not up at the time try to springboard out the arena or try a normal wall.

Ripclaw
The hardest one for me. The biggest change is a damaging roar that i found no additional signs that differ from its regular roar, this always one shot me. As soon as any signs of a roar are coming spring board out of there.

As long as you keep the celestial shield up and avoid one hit kills these are doable in a few tries.