Hi, I am making a homebrew subclass for the 2024 sorcerer inspired by the frenzied flame from elden ring for one of my players. I spent some time on it and was a little unsure if it was balanced or not and if it would end up doing more harm then good to the party. Eventually I brought it over to some friends and they seemed to think it was fine. However, I would also love to hear some neutral feedback from people with more experience at creating homebrew. 

The idea I had in mind when creating this subclass was trying to incorporate elements from the frenzied flame in elden ring (like self damage, revival, madness, etc.) and I feel like I managed to include most of what I wanted. The subclass did however end up a little cramped, especially at level 3. In general it is fine if it is strong as long as it won't overshadow the other players in the party. That is why I added drawbacks to a lot of the stronger abilites in the subclass.

This is the subclass and any feedback is appreciated!

Frenzied Flame

Here's my initial thoughts.

• Interesting concept and has unique features - all of which are flavorful, so I really like that.
• In general, I think this is fairly balanced and wouldn't cause issues in a group unless they were trying to optimize it and/or exploit loopholes. 
• Frenzied Rebirth has the biggest potential to be overpowered, but it seems like it could be balanced and is hard to tell without lengthy playtesting.
  • I would make the 2d10 Fire damage pending a Dexterity save (half on a success).
  • I would remove the fail by 5 or more condition or have some lasting effect on the player like taking damage as the DM can attack or use a fire spell if they fail by any number.
  • How do you anticipate this working outside of combat (e.g., a player dies outside of combat or they're still making the saving throws after all enemies are defeated). Do they initiate combat against the party (or random NPCs nearby)?
  • Is there a certain number of failures that can result in permanent death? What if the player dies again while still making the saving throws?
• The 1 on Frenzied Surge is particularly punishing. I would recommend just having it damage the caster (or remove the damage and have it not be cast).
  • I would remove the damage dealt to the player on 4-5 as it's very little and adds some extra complexity. The damage is particularly low given the resistance you gain a few levels later.
  • I would phrase this as "You cast the spell again" rather than the "Spell casts itself again" so you're clear on the spell attack, saving throws, and that the player has the choice of who to target. This also has a significant impact on a Concentration spell as if the player is not the one concentrating on it and the spell then lasts for the full duration, you end up in overpowered territory.
• I would remove the 1d4 rounds for for Blinded and Frightened. Either make this 1 minute or until the start (or end) of your next turn. Rounds are a pain to keep track of for individual monsters and you have the mechanism for them breaking it by repeating the saving throw at the end of their turns. If you want it to always be short, then the end of their next turn is a good way to handle that.
  • Charisma seems like an odd fit for a saving throw on this. Dexterity would normally be to avoid damage, Constitution (or Dexterity) to avoid blinding, and Wisdom to avoid Frightening. Any of those three would seem to make more thematic sense.
  • As they take the 2d10 Fire damage regardless of the save, it might be better to pull it out of the saving throw to make this read easier - they take 2d10 Fire damage and make a X Saving Throw.
• As a capstone feature, I'd be open to seeing it in playtesting, but an average of 55 (+5.5 per death) Fire damage (unresisted) without a saving throw seems too powerful. You could cheese the subclass by having the character die a bunch of times if there's no chance they can ever permanently die and then with the Level 18 feature, they can one-shot everything without a saving throw.
  • Having allies be affected does tamper the power a bit, but it can be avoided easily enough.
  • I'd recommend a saving throw with half damage on a success for the baddies.
  • I'm unsure on the exhaustion and the impact. It feels like it could be important by expending sorcery points to use it again.
  • You might want to specify (no action required) for regaining the use of the feature.
  • I'd recommend having this be a "Magic" action (for consistency with similar abilities and to avoid action surging it - granted you'd have to be Level 20)

Awesome, I particularly like the changes to level 18. Had not really thought about it being overpowered since it also damages allies, but you do make a good point on why it needs a nerf. 

It's very flavourful, but I'm not sure it would actually be fun to play.

A few comments:

• The sheer number of spells known is going to make this character extremely versatile. You are giving them for free damage spells, utility spells and control spells, plus they get all their regular known spells on top! If you have another spellcaster in the party it's quite likely to overshadow them simply due to the number of solutions this character will have to every problem.
• Frenzied rebirth is interesting from a mechanical perspective but I suspect it wouldn't actually be fun to play at the table. Having the DM take control of your character means that that player is just sitting out the rest of the combat which is no more fun for them than if their character had remained dead.
• Frenzied surge again is interesting from a mechanical perspective for sure, but is it going to be fun in actual play? Is a 5th level sorcerer double-fireballing on the first round of combat and completely wiping all the enemies going to be fun for you as the DM? for the other players? Is having their biggest spellslot of the adventuring day be wasted because they rolled a 1 going to be fun for the player?
• For Frenzied Surge how is it meant to work with concentration spells? Can I get two simultaneous Cloudkill spells out of it?
• Burning Maddness just means this character doesn't need to take any other damage spells so all of their normal sorcerer known spells can be used to take utility & control spells again enhancing their versatility.
• Burning Eyes of Frenzy is fine, but just runs contrary to standard design, Fear effects are almost always Wis saves, and blinded is almost always a Con save, Cha saves are restricted to extra-planar effects. Likewise 1d4 rounds is just annoying to keep track of, make it 1 round or 1 minute.
  • Frenzied Inferno... I think is just a bad feature. It is likely to hit my allies, and the damage is only a bit higher than what could be achieved with a normal spell, and it seriously penalizes my character to use it. At these levels I could instead cast a 7th level Fireball for 42 fire damage without all the penalties and a chance to add +10 damage to it or to cast it twice in a row.