Lowest Tier Character that can Conquer the World?

Who is the lowest tier character who can conquer the world?

Rules:

They only get one life, but the governments of the world cannot use nukes or weapons at around that level of power. The world has no knowledge of the character and the character gets a week of prep. They can use any weapon that they would reasonably have access to as well.

Round 1:

Modern Day

Round 2:

1865

Round 3:

1400

Saints Row Boss. Dudes a serial killer, criminal mastermind, and world wide celebrity, he even became the President of the US.

Purple Man.

Light Yagami could take rounds 2 and 3 for sure as well as anyone with telepathy logically should be able to take over the world without many issues

Garrosh Hell- Oh, LOWEST TIER CHAR? ..............probably tony stark.

Crow from timesplitters future perfect

he has the time device and can make his timesplitter army

hmmmmm i agree