Sanctuary Game (LitRPG): I Can Synthesize Infinitely

Synthesize [Sanctuary Core] and [Remains of the Deep Sea Behemoth] to obtain the Portable Bio-Replicator Sanctuary.
Synthesize [Goddess Statue] and [Divinity] to obtain the Obedient Goddess Maid.
Synthesize [Spear] and [Dark Blood] to obtain the Divine Artifact: Godslayer Spear.
...
As darkness descended upon the Earth, it brought forth the malevolent gods and countless terrifying monsters, along with various horrifying natural disasters.
Extreme cold!
Severe drought!
Insect infestation!
A sanctuary game brought vitality to humanity.
Players can obtain an upgradable sanctuary and various magical opportunities in the game.
Charles awakened with the talent of unlimited synthesis, embarking on a path of infinite synthesis...