Arcane Dominon

You summon a demiplane centred on yourself (personality, traits and values). It transforms the surrounding environment around you up to the edge of a 80ft radius. At the edge of the demiplane is a barrier, on summoning a demiplane you can choose one of the two conditions: 

No creatures can enter the demiplane by physically walking in or flying out

Or 

No creatures can exit the demiplane by physically walking out or flying out

Your demiplane consists of a landscape, atmosphere and treasure 20ft in all dimensions . If summoning an old arcane dominion you retain the same landscape, atmosphere and treasure as when you created it. If summoning a new one, the old one disappears and you create the arcane dominion as follows: 

Landscape: Roll 1d8, if number is: 

1 – Grasslands 

2 – Island 

3 – Desert 

4 – Forest 

5 – Arctic area 

6 – Cave area 

7 – Castle area 

8- Mountainous area 

Atmosphere: Roll 1d8, if the number is: 

1-  Orange sky with blue sun 

2- Purple sky with green moon 

3 – red shooting stars 

4 – No sky, black visible barrier 

5 – Black sky with blood moon 

6- Golden moon with purple sun during eclipse 

7 – Purple clouds, night sky 

8 – Blue sky, fragmented planet in background 

The treasure of your demiplane can look like anything the caster desire provided it is clearly visible when the spell  is initially casted. When the spell is casted the treasure can be spawned anywhere in the demiplane that the caster desires. The treasure has a hp of 3 times the caster’s max hp and has an AC of the caster’s base armour + DEX mod. The treasure provides a permanent feature and a passive feature to the caster for the spells duration. The passive feature begins in the first round of combat if the caster is in a combat situation.

Permanent feature: Roll 1d8, if your number is: 

1 - You gain advantage in all saving throws and attack rolls 

2-  You have +5 AC 

3- All creatures hostile to you are near-sighted and can only see in a 15ft radius 

4- Name a spell school. Spells of that school used by enemies have no effect 

5- You can concentrate on two additional spells 

6-You can sense everything in your domain

7-Natural 1’s  your roll on a 1d20 can be rerolled 

8- You can take 2 reactions each round 

Passive feature, Roll 1d8, if your number is: 

1-You gain +20HP every 5 rounds 

2-Every 5 rounds all enemies are forced to make a constitution save against your spell save DC. On a failed save they take 1d6 + 4 radiant damage and are moved 10ft. On a successful save they take half damage and are moved 5ft 

3-Every 5 rounds, you can temporarily add 4 points to a score of your choice that lasts 3 rounds

4-As a bonus action you can summon up to three creatures that are hostile to your enemies and friendly to you every 10 rounds. They disappear after 5 rounds. The creatures can be of any CR provided that their added CR’s does not exceed yours. 

5-Every 5 rounds you regain a spell slot of your choice

6-Every 10 rounds all enemies gain a 2 levels of exhaustion and you gain 40HP 

7-Every 3 rounds you can take a bonus action to teleport anywhere in your arcane dominion 

8-Every 5 rounds as a bonus action you can cast a spell that you know without using a spell slot

When dispel magic is used on all the treasures and it succeeds the spell ends. This spell can be counterspelled after it has successfully been cast, however if the counter spell fails the arcane dominion can only be counterspelled by a counter spell upcast to level 9 until the spell ends. 

If two arcane dominions are cast at the same time or another caster's dominion would overlap yours. Both should make a constitution save. If your number is bigger their spell fails and your dominion stays for the spells duration. If your number is smaller your dominion collapses and you take two levels of exhaustion. If you lose concentration the spell ends.

If the spell ends and you summoned an old arcane dominion you get 1 level of exhaustion, if you summoned a new arcane dominion you get 3 levels of exhaustion. At level 18 you can have two treasures