Okay you guys have two choices

normal holy grail war

or

The greater holy grail war so like well just like fate/Apocrypha

The reason why he went to a new world so early on is that depending on what you guys choose will change how the mc world will change if the choice fate/Apocrypha then there need to be a reason why which is the MC is lekking mana but it will be on larger amounts of mana so he will need to be off his world to get his magic circuit to a high level and have his gen high level so it will leak out a large amount of mana in which case the grail will evolve.

Thank you Tigre_Valentine for this

the grades are: common, uncommon, epic, and legendary. the higher the grade the harder it is to land. common: " this is useful stuff but has no supernatural powers so no food from food wars because of the reaction it brings. so like a can of beans, a large tent, a grill. this is what the common should be. Uncommon: " this is for things of simple magical powers. an example a sword from Skyrim enchanted with ether the original Skyrim enchantments or some less powerful mod ones. this is where food from food wars is because it's absolutely delicious but doesn't have anything to do with the MC power, that is what earns it a place among uncommon. rare: This is the place for powerful healing items like phenex tears from highschool dxd or a weapon that is powerful but isn't straight up overpowered like pumpkin from akame GA kill. it could also be for training manuals that the MC has to learn himself. Legendary: " this category is for the truly power items, these are mostly weapons like demon extract from akame GA kill or the boosted gear. this could also be the only category that has skills in it. now for the quests rewards. 1 star: this is quests like do 30 push ups. the reward would be the healing of Exhaustion. the reason is because the host wasn't in danger and didn't do anything that affected the main plot. 2 star: this is for low threatening quests like hunt a wolf or kill five bandits. the reward would be a higher understanding of a subject that is selected by the system. 3 stars: this is for quest that have a higher chance of dying like hunt a dangerous monster or wipe out a bandit camp. the reward increases by the danger of the beast or the number of bandits. the reward could be the cooking skills of a character from food wars or the knowledge of a martial art. 4 stars: " these are quest that have powerful enemies that need to be killed. an example is zanku from akame GA kill. the reward a power that the character has or the items off the characters. 5 stars: these quest are for boss level enemies or plot changing events. the reward is really high because of it's importance the reward could be unlimited amount of mana or a powerful skill like one of the 10 commandments power from seven deadly sins. this what I thought the system should be, because you don't want a overpowered MC I thought this would work because he would start out weak but become overpowered near the end of the story. this point is where you go to dragon ball z universe and end the story there. but this is all you.

Worlds: Anime (+1= if you want the mc to go there while 1,2,3,4,5 is the level you think the world are after read above)

The Asterisk War

That Time I Got Reincarnated as a Slime

Sword Art Online

Naruto

Naruto Shippuden

God Eater

Hand Shakers

High School DxD

Fullmetal Alchemist: Brotherhood

DARLING in the FRANXX

World Break: Aria of Curse for a Holy Swordsman

Bleach

Isekai Cheat Magician

Akashic Records of Bastard Magic Instructor

RWBY

Is It Wrong to Try to Pick Up Girls in a Dungeon?

Dragon Ball (all)

Fairy Tail

Attack on Titan

My Hero Academia

The Rising of the Shield Hero

The Irregular at Magic High School

Demon Slayer

Black Clover

JUJUTSU KAISEN

Saint Seiya

Twin Star Exorcists

Wise Man's Grandchild (i was thinking it was Grandson not Grandchild)

The Testament of Sister New Devil

One Piece

Campione!

Hundred

Bladedance of Elementalers

Death March to the Parallel World Rhapsody

In Another World With My Smartphone

ALDNOAH.ZERO

D.Gray-man

Chrome Shelled Regios

Date A Live

Hunter x Hunter

infinite stratos

Rosario + Vampire

Tokyo Ghoul

The Seven Deadly Sins

Soul Eater

Sky Wizards Academy

Seraph of the End: Vampire Reign

Noragami

Lord Marksman and Vanadis

Knight's & Magic

Kaze No Stigma

K Project

Aesthetica of a Rogue Hero

Absolute Duo

[Suggestions]

Worlds: TV shows/Movies (+1= if you want the mc to go there while 1,2,3,4,5 is the level you think the world are after read above)

Transformers

[Suggestions]

Power/bloodlines/weapons/items: it can be anything (+1= if you want the mc to have 1,2,3,4,5 is the level you think the power/bloodlines/weapons/items are below)

Water bending

air bending

fire bending

earth bending

[Suggestions]