Explain to me how Sun Disk Gear works then give me an example.

The Sun Disc is a Gear card (Domain: Fury, Cost: 2 Energy, 1 Power) that features an activated ability.

How Sun Disc Works

1. Playing the Gear: As a Gear card, you must play it to your Base (Rule 146.1.a.1). It enters play Ready (Rule 147.1).
2. Activated Ability: The card has the ability: [T] : [Legion] — The next unit you play this turn enters ready. (Get the effect if you've played another card this turn.)
   • Cost: To use this ability, you must exhaust the Sun Disc ([T]).
   • Timing: You may only activate this ability during your Action Phase while in an Open State (Rule 148.2).
   • Legion Keyword: This is a conditional effect. You only gain the benefit if you have already played another card earlier in the same turn.
   • Effect: If the condition is met, the very next unit you play during that turn will enter the battlefield Ready (instead of the standard state for units).

Example Scenario

Imagine it is your turn and you have already played a spell (e.g., a "Draw" spell) earlier in the turn.

1. Setup: You have a Sun Disc on your Base.
2. Activation: During your Action Phase, you exhaust your Sun Disc to activate its ability. Because you already played a spell this turn, the [Legion] condition is satisfied.
3. Resolution: The ability resolves, creating a game effect that applies to the next unit you play.
4. Playing a Unit: You then play a unit card from your hand. Normally, units enter play and must wait to act, but because of the Sun Disc's effect, this unit enters the battlefield Ready. You can now immediately use that unit to attack or perform other actions that require it to be ready.