Arcana

Rule 11: Arcane spellcasters may personalize their spells however they wish.   You want your magic missiles to look and sound like photon torpedoes fired from the USS Enterprise then that's what they do.    You want your teleport to be a subtle fade away or in, or do you prefer it to be a large explosion of black smoke like that of the Wicked Witch of the West?

Once a spell is personalized, that's the default.   If a Arcane spell caster wants it to be something different to mimic another caster or hide their style, they may alter it on a successful Arcana check against difficulty 10. 

This concept is gone into with more depth in the video below.

Religion

Rule 12: Divine spellcasters have spells that are personalized by their Empathic interpretation of the Power they serve.  The target of a follower of Sune may feel themselves engulfed in the warm waters of Evergold whenever they receive a healing or protection spell.   A target of a follower of Lolth may feel themselves covered by hundreds of spider from the same spells.  

Once a spell is personalized, that's the default.   If a Divine spell caster wants it to be something different to mimic another caster or hide their patron, they may alter it on a successful Religion check against difficulty 10. 

Rule 13: Class Animal Companions gain levels equal to that of the character they serve, as if they were a Champion fighter of the same level, in addition to their normal abilities.   If slain, it may go through the process of being raised from the dead if qualified, though it must pay the penalties like any other character. 

If the same character had more than one animal companion, the total character levels must be split between them equally, with the any excess going to the favored Companion.  Each animal companion gains 84 attribute points just like their master, with the excess of their base template being spread logically by their master. 

We'll get into this more with a future update of magic interpretations.  

Rule 14: Familiars gain half of their master's hit points.   They gain 84 attribute points just like their master, with the excess of the base template being spread logically by their master. 

Unless specifically blocked from doing so, the spirit may cross between its summoned plane and the plane of its master at will.  If slain, it must be resummoned.

We'll get into this more with a future update of magic interpretations. 

Rule 15: Summoned Mounts gain half of their master's hit points.   They gain 84 attribute points just like their master, with the excess of the base template being spread logically by their master. 

Unless specifically blocked from doing so, the spirit may cross between its summoned plane and the plane of its master at will.  If slain, it must be resummoned.

We'll get into this more with a future update of magic interpretations. 

Rule 16: Death should suck.   This is not a video game with a respawn, that just leads to players being self destructive as death has no meaning.

Thus, the following limitations and penalties will apply to anyone who has been dead longer than the 1 minute limitation of a revivify spell.

Raising the dead will cost a level and 1 permanent point of constitution in addition to all other costs listed in the spell.   Though anything from a Greater Restoration to a Wish spell may restore the level, the constitution lost may only be replaced by buying the point back through leveling or other process outlined in Rule 2.

This means any character or creature that has not achieved at least two levels may return from the dead.   Even an ancient dragon is forever dead, unless it had adopted a character class and achieved at least level two.   Hit dice are not a substitution for leveling.

In addition, no character or creature with a constitution score of 3 or less may be revived.   Other steps would have to be taken to make that possible, if that was even still in the realm of possibility. 

The spirit must also be willing to return.  For example, torture victims rarely choose to return to their captures. 

The spirit and the corpse must also survive a system shock roll.   The difficulty of this roll is the character's constitution score subtracted from 20.   This means that those with Constitution Scores above 19 can only fail on a Natural "1".   A Natural "20" will succeed no matter what. 

Failed rolls count.   The character must deduct total levels and total constitution points for both failed and successful raise attempts.

With this homebrew, the number of characters and creatures that can be raised are rare.  Further, nothing can be raised an infinite amount of times.

There are reasons why people go to other extreme means to try and survive death's permanent embrace...

Rule 17:  Reincarnation isn't so hard to achieve.  The reroll is available to all life and any living thing can refuse to be reincarnated (prior to the roll). 

It isn't like Reincarnation in an Isekai.   You are not the same exact character in a newly ungraded body, in a new place. 

The spell will remake you into something else.  Even with memories, it means the end to that character.  There is also the random factor to it.

A new personality and creature will emerge.   A player can keep the levels in some form, but the old character is undone in the end.   Wish and blessing raised stats, as well as other personal touches will be gone.   

A new random character will take that place. Anything the previous character earned in the afterlife is now gone, as the spirit desperately clings to life, by destroying what it was.

That said, I'm not going to be completely awful to the player.  As a fan of what Doctor Who was, a character will have its chance to say goodbye...

Rule 18: Hero Points and Dark Points

Hero points and Dark points are gained at a rate of ten points 10 + two times the character level in points.  Thus, a 1^st level character would have a potential 12 points and a 20^th level character would have a potential of 50 Hero points or Dark points.

These points are not regained automatically.  They are a reward for a player playing their character well and playing well with their team.  The character is judged on how the concept lives up to its alignment, nature, demeanor, virtue, and vice.  The player is rewarded for exceptional play, good integration with the team, and the good times they bring to the group.

These are awesome abilities.  It should be noted that these are not limited to player characters.  There are Heroes and Villains in the world who also have access to these points.

It should also be noted there is no way to restore hero or dark points in a session.  They are recharged after a session by the DM.

Hero or Dark points may be spent to:                                                       

-take an additional action (one per turn only)

-make an additional attack (one per turn only)

-cast an additional spell of any level

-maximize one damage dice per point spent

-maximize one healing dice per point spent

-Ignore a fumble (bad side effect from a Natural “1”)

-Substitute one known spell for another

-add +2 (or +10%) to the result of any dice roll before rolling

-add +4 (or +20%) to the result of any dice roll before rolling (for two points)

-double the area of effect of a spell

-double the distance of a ranged attack (martial or spell)

-multiple the duration of a spell as follows: 1 point for x2 duration, 2 points for x3 duration, 3 points for x4 duration, 4 points for x5 duration, 5 points for x6 duration, 6 points for x7 duration, 7 points for x8 duration, 8 points for x9 duration, 9 points for x10 duration  

-pierce with a martial attack or spell (potentially hit another target behind the first for the same damage).   If more than one target is behind the first, you can spend as many points to pierce as many targets that exist, as long as each one hits.

-cleave with a martial attack or spell (potentially hit another target near the first in melee weapon range by blunt or slashing attack, for the same damage).   If more than one target is beside the first, you can spend as many points to cleave as many targets that exist, as long as each one hits.

Rule 19: Attunement

DND 5E limits characters to 3 attuned items.   As this is a weird nerf to older players, the following homebrew adds more attunement slots as the characters level:

Levels 0-2: 3 attunement slots

Levels 3-5: 4 attunement slots

Levels 6-8: 5 attunement slots

Levels 9-11: 6 attunement slots

Levels 12-14: 7 attunement slots

Levels 15-17: 8 attunement slots

Levels 18-20+: 9 attunement slots

It should also be noted that characters do not attune to Artifacts and Relics.  Through side effects and other negativities, these ultimate magic items attune you to them.  A character could potentially carry an unlimited amount, but nothing could survive that.