Terraria – sync players and worlds between multiple computers

This is my entire process on how I've beaten the eater of worlds. It is not my intention to brag, but instead provide credibility; using these exact steps, I have defeated the eater of worlds using a brand new hardcore character without the assistance of any other players or items.

1. Obtain all of the following:
   • At least iron armor (or better) - set bonuses help
   • Gold bow
   • 250-500-ish arrows (some flaming arrows greatly help)
   • several suspicious looking eyes
   • several vacant houses for NPCs
2. Brew several archery potions, ironskin potions, regeneration potions, and healing potions
3. Under the effect of all buff potions, summon the eye of cthulhu and defeat him. Depending on how fast you are at this point in the game, you may or may not be able to defeat more than one per night. If the moon is past the halfway mark in the sky, don't summon another until the next Terrarian night.
4. After obtaining enough demonite ore, craft a war axe of the night and demonite bow.
5. Talk to the dryad to obtain purification powder, or the demolitionist to obtain bombs, and head over to the corruption. using either to access shadow orbs, break 3 of them (keep in mind the third will summon the eater of worlds). If any of these drop from shadow orbs, you can use them as weapons:
   • Musket - an excellent ranged weapon, especially for this stage of the game.
   • Ball O' Hurt - An excellent weapon to fight against the eater of worlds. Definitely a good idea to use it during the boss battle.
   • Vilethorn - if you have any mana, using this whenever possible is highly recommended. Cast it parallel to the eater of worlds' body for maximum damage.
6. When the eater of worlds is awakened, you'll want to be equipped with the following for the boss fight:
   • War axe of the night
   • Several ironskin potions, regeneration potions, and healing potions
   • Several grenades, if possible (arrows or musket would work too)
   • Any shadow orb weapons, and an ample supply of mana if using the vilethorn
7. Chances are you'll be in a pit, and this is actually a good thing since it protects you from any eaters of souls (which are a nuisance during the boss fight). Use several wooden platforms so you can navigate vertically, and start swinging your war axe or flail.
8. During battle, simply move next to or below his body when it attacks you so you can deal constant damage with your weapon. If you're confident you aren't going to hit yourself, lob a couple grenades, as they do a hefty 60-ish damage to multiple segments.
9. As segments die, they drop hearts, which are instantly collected at melee range - this greatly improves your survivability at this stage of the fight. If you die partway through, you'll still have a few shadow scales - see if you can make a piece of shadow armor, and attempt the boss battle again.

Repeat these steps until you have full shadow armor. Equipping this full set and an ironskin potion makes the battle a walk in the park. At that point, you don't even need to artfully dodge his attacks; just sit there swinging your axe and reap the rewards.

Crimson appears to be a substitute to the Corruption. The first world I created after installing the 1.2 update contained a Crimson biome, which also happened to take over a neighboring desert. Various differences with Crimson include:

• Crimstone replaces stone
• Crimsand replaces sand
• Crimtane Ore replaces Demonite Ore
• Crimson Altars replace Demon Altars
• Demon Hearts replace Shadow Orbs
• A few unique item drops
• A few unique enemies (Blood Crawler, Face Monster)
• A unique boss (Brain of Cthulhu)

Otherwise, I'm pretty sure Crimson can essentially be considered an equivalent to Corruption (it appears to spread over time in the same fashion, for example).