The “Colossus” artifacts give a bonus to one or more of the base stats of the celestial body which it is active on. The bonuses vary, dependent on the biome that the artifact originated from, but will always give a bonus to the Speed stat. This bonus scales from 5% for a Common artifact, up to 15% for a Mythic artifact (or even more, depending on the biome!).
There is nothing unintuitive about the “Colossus”, or any of the other stat-boosting artifacts - they can be activated and deactivated as many times as you wish, can be used on any level of celestial body, and will provide their bonus instantly (once the blockchain transaction is confirmed).
This planet has a “Colossus” on it. Watch out for quicker attacks coming from here - don’t be caught off guard!
In the Early game, Speed is a decent stat for an artifact to provide (not the best, though). It is preferable to Defense, but less impactful than Range. A “Colossus” artifact will shine best if you have any celestial bodies with a x2 Speed Moon - since the artifact bonus is a multiplier, it is essentially twice as effective here.
In the Mid-Late game, unfortunately, due to the nature of the game where rounds often go on for several days, a small boost to Speed might only reduce an attack from 6 hours, down to 5 hours… and what’s really the difference, there. If you need a speedy attack, it is almost always better to use even just a Common Photoid Cannon, as any long range attack will likely land faster, even with the 4 hour waiting before the Photoid Cannon is ready.
The stats provided by an Epic Desert Colossus - unfortunately, they aren’t that epic. Kek.
As you can see, there is only a bonus 30% speed provided by this Epic Colossus, which is less than half the bonus provided by a single upgrade into speed on a planet. See the chapter on Speed for more information. Whilst it may save you some time, it likely won’t be a particularly useful artifact in many situations.