Of course you will need Ingredients!
Here they are.
1 of each:
Spear
Tentacle spike
Ham Bat
Glass cutter
Dark sword
Terra blade

And that's what you need!

To craft the Zenith, you need the new crafting station(S), found in Science, The Mythril anvil and
Orichalcum anvil! First, we need to talk about the new cave system, Deep Beep Caves! Much more creatures and ores are down there, with new plants and turfs! Also comes with new music! You can find Orichalcum and Mythril chunks in there, along with new ores! To mine these ores, you need a T-rank pickaxe! These pickaxes are T-rank: Demonite pick, Crimsonite Pick, Orichalcum Pick, Platinum pick, and Mythril pick! At the new crafting table found in Science, you can get the Furnace! There you can smelt ores for bars! You can use these bars for materials! Craft Orichalcum/Mythril bars to then craft the Anvils(S). Now you can start crafting!

Since there is more ingredients than 3 in the Zenith recipe, it needs a DIY kit. Costing only 3 grass, the ZenIY kit can be found in Fight. Click on the ZenIY kit on your inventory or ground, to open a KIT menu. It will need ingredients. You might say, "How do I get the Terra blade?" In the Deep Beep caves, There are dungeons protected by Skeletron. You need to defeat him first. In one of the chests, there is a 90% chance to get a Terra blade. Now you can start crafting!

Equip it to have unlimited durability, 120 damage, and a very cool Light thing that hurts a ton! It has the range of 10 turfs long, and counts as an electrical weapon, so it does WAY much more damage on wet targets!

I hope you enjoyed this guide! I hope it helped as well. Goodbye!