Traveling across Douluo Continent, Ye Han, originally planning to curry favor with a powerful opponent, unexpectedly obtains a 2D system, allowing him to summon characters from that world!

...

Summon Esdeath, the Ice Queen, a Control-type.

Summon Artoria, the King of Britain, an Attack-type.

Summon...

Even if Tang San is the protagonist, he still has to fight!