As Lavabrink Venturer enters the battlefield, choose odd or even. (Zero is even.)
Lavabrink Venturer has protection from each mana value of the chosen quality.
For spells with {X} in their mana costs, use the value chosen for X to determine the spell’s converted mana cost. If a permanent or card in any other zone has {X} in its mana cost, X is considered to be 0.
If Lavabrink Venturer somehow has no choice made for its ability, its last ability grants it no protection abilities.
The converted mana cost of a token that isn’t a copy of another object is 0. A token that is a copy of another object has the same converted mana cost as that object.
You choose odd or even for Lavabrink Venturer before it enters the battlefield. There’s no point at which players can target it before it has gained the appropriate protection abilities.