Mark of the wildcard

With every long rest, your body and mind is drawn to a specific fighting style as your inspiration from a dream. On each long rest, you gain on of the following effects until your next long rest by rolling a 1d15 (or 1d30 if any.) to determine which one you get. You have a mark on your body that changes depending on which class you get. That mark may have been left on you by a supernatural being or an artifact, or you may have been blessed by it when you were born but manifested itself later on. That mark inspires you with knowledge for that day and you forget the knowledge once you rest.

1. Fighter: You gain access to one use of action surge.

2. Cleric: You gain one of four cantrips by rolling a 1d4 to determine which one. You can use the cantrips an amount of times equal to your proficiency.
1. Guidance: You touch one willing creature. Once before the spell ends, the target can roll a d4 and add the number rolled to one ability check of its choice. It can roll the die before or after making the ability check. The spell then ends. 
2. Healing aura: You restore hitpoints to a creature you choose that you touch equal to your wisdom modifier, with the minimum of 2.
3. Toll the dead: You point at one creature you can see within range, and the sound of a dolorous bell fills the air around it for a moment. The target must succeed on a Wisdom saving throw or take 1d8 necrotic damage. If the target is missing any of its hit points, it instead takes 1d12 necrotic damage.
4. Thaumaturgy: 

You manifest a minor wonder, a sign of supernatural power, within range. You create one of the following magical effects within range:

• Your voice booms up to three times as loud as normal for 1 minute.

• You cause flames to flicker, brighten, dim, or change color for 1 minute.

• You cause harmless tremors in the ground for 1 minute.

• You create an instantaneous sound that originates from a point of your choice within range, such as a rumble of thunder, the cry of a raven, or ominous whispers.

• You instantaneously cause an unlocked door or window to fly open or slam shut.

• You alter the appearance of your eyes for 1 minute.

If you cast this spell multiple times, you can have up to three of its 1-minute effects active at a time, and you can dismiss such an effect as an action.

3. Ranger: You gain a favored enemy that you have an advantage on tracking. That favored enemy must be a creature you've encountered in the previous day. You additionally gain access to hunter's mark if you don't have it, regardless if you do or don't, it doesn't require concentration to use and can be used at will the first time you use it. If you already have hunter's mark, you can choose a 1st level spell from the ranger's list instead. It does not count towards your learnt spells. You additionally gain a favored terrain and have no disadvantage in traversing while that terrain through difficult terrain.

4. Paladin: You gain the ability to use lay on hands, and the amount of points for it is equal to your proficiency bonus+Your charisma modifier, to either restore hitpoints of a creature or cure a negative effect. You additionally can use divine smite only once of any level, but the maximum damage is still 5d8, and still requires a spellslot to use.

5. Sorcerer: Depending on if you're able to cast spells or not, you gain different effects.
1. Not caster: Whenever you make a weapon attack against a creature and roll a 3 or less, you roll on the sorcerer's wild magic table.
2. Third caster: Whenever you use a spell, additionally roll on the sorcerer's wild magic table twice and pick one of the two effects.
3. Half caster: Whenever you roll on a spell, and you roll either a 10 or 1, roll on the sorcerer's wild magic table, and if you take damage from it, you only take half damage instead.
4. Full caster: Whenever you roll a 20, you can roll on the sorcerer's wild magic table twice and choose which one of the two effects you want to happen. You can pick both effects, but you must always pick at least one of them. The effect/attack would also be considered as a critical hit if applicable as if you rolled a 20 on that.

6. Wizard: You can choose to gain one of the two following effects:
1. When you cast a spell that adds a modifier of an ability score, you can additionally add your INT modifier to it. If the modifier is INT, then you can add it twice instead of once. Additionally gain a cantrip from the wizard's spell list.
2. You gain two level 1 spell slots that you recover on a short rest, and the spell Elemental ball which you can cast using only those spell slots.
Elemental ball: Range 100ft, school transmutation, casting time 1 action, components V and S, Duration instantaneous. You stick out your palm or limb and form a ball of pure elemental energy then fire it towards a direction. You can choose it to be ice(cold), light(radiant), darkness(necrotic), fire(fire), lightning(lightning) and it deals your proficiencyd6 damage+INT. Your spellcasting modifier is INT, and you add your proficiency. Once the orb hits a creature or object, if you missed your main attack or succeeded, it additionally explodes in a 15x15 feet dealing your proficiencyd4 damage to any creature that fails a DEX save of Double your proficiency+Double your INT modifier with the minimum of 2. 

7. Bard: You can pick two proficiencies in either Performance, Deception, Persuasion, Intimidation. If you have proficiency in one that you picked, you gain expertise instead. You also gain proficiency with a music tool of your choice. You can add your CHA modifier to any rolls related to those four. You additionally have the ability to cast cure wounds only once. You gain a language of your choice. 

8. Rogue: You can pick two proficiencies from Stealth, Sleight of hand, Acrobatics, Thieves tools. If you have proficiency in any of the ones you picked, you can gain expertise in it instead. You additionally can speak Thieves cant. You can deal sneak attack damage equal to your proficiencyd6 only once.

9. Monk: Choose one of the three effects to gain:
1. When you cast a spell on a creature, you can expend a spellslot equal to that spell to either heal twice the spellslot level d6+ your spell modifier or attempt to stun the creature with a CON DC save of twice the spellslot level+your proficiency+The spell modifier on the creature you targeted with the spell, until the end of it's next turn.
2. You can use flurry of blows as a bonus action. This does not require ki to use. Each hit would deal 1dyour proficiency rounded lowest even die+ Your strength or dexterity. You can add your proficiency and either strength or dexterity to your attack roll.
3. When you use a ranged weapon attack or a weapon with a thrown property as a ranged attack, you can add your proficiency to your damage if you are proficient with that ranged or thrown weapon. 

10. Artificer:   You have advantage on investigation and arcana checks related to built objects or magical items, and gain a +5 to your passive investigation.  You additionally gain two cantrips of your choice from the artificer's spell list.

11. Druid: You can speak druidic. Additionally, choose one of the two effects to gain:
1. You can use wild shape to transform into a creature with a CR equal to half your proficiency an amount of times equal to half your proficiency for an amount of time equal to 2xyour proficiency.
2. You learn two cantrips from the druid's spell list.

12.  Warlock: You can pick one of the following effects:
1. You gain a warlock spell level equal to half your proficiency. You can't pick this if you have no spellslots.
2. You learn the cantrip eldritch blast and gain one eldritch invocation of your choice.
3. You can deal an additional 1d6 (increases by 1d6 each 6 levels) necrotic damage on a melee weapon attack once per turn.
4. When you kill a creature with a weapon attack, you regain hitpoints equal to half it's constitution. Any hitpoints over your maximum would turn into temp hitpoints. You can use this effect an amount of times equal to half your proficiency.

13. Barbarian:
You can choose one of the following effects to gain.
1. You gain the ability to enter a frenzied rage.
2. You gain the ability to attack with a +5 to hit but a -5 to damage.
3. When you attack using a ranged weapon, thrown or spell, you can roll a 1d20, if you get a 20 then you can attack an additional time using that same attack or spell. It still requires resources like ammunition or spellslots as it normally would, and only on the same target. You can roll a 1d20 again on each following attack by this effect as well potentially making an infinite amount of attacks.

14. Void: 
You either did something very wrong that made the deity, god or creature that gave you the mark upset or something went extremely wrong.
You lose a skill proficiency and expertise of your choice, additionally you have a -2 on all rolls related to that ability. You also forget a random language you know. (Could be common too) Your highest spellslot is locked, meaning you cant use it.

15. Destiny: 
This day is a day that you were destined for to go exactly as the god/deity or being that gave you the mark. You roll a 1d20  store the roll. You can switch any of your rolls to the outcome of the roll you stored instead at any time you choose, then the dice you chose is expended. You additionally can turn a disadvantages into an advantage, and you can only use this once. You gain a cantrip of your choice. You can choose to use this effect either as healing or damage. If you chose healing, then you can roll a 3d10, then you can heal any creature by that amount on will with the range of touch. If you chose damage, then choose a creature, both you and that creature roll a your proficiencyd10, and whichever rolled lower take that amount of damage somehow by fate, either by a boulder falling on them, or by tripping down a cliff and so forth. (DM decides) within the next minute. You don't get to know the outcome unless you see, hear etc.. it happening to that other creature or yourself.