magic I dont get Coalition Relic how it works

[SlowFast]

dont understand Coalition Relic what good is its second ability if you wont be able to get more then one counter on it anyway because they are all removed every turn?

[Void Elemental]

Using the second ability allows you to remove a counter to add 1 mana of any color to your mana pool, then tap the Relic for the first ability to add another.

[Arix]

Imagine this scenario. You play the Relic on turn 3. Tap it for a counter at the end of your opponent's turn. During your main phase, you remove the counter for one mana, and tap the Relic for another. That's a two mana boost.

Or, you could mess with the counters usnig things like Gilder Bairn, Doubling Season, or proliferate.