If you are talking how much actual power it needs to get going, technically by sensitivity and impedance ratings, the ananda is going to be the least demanding, and then followed by the elex (which admittedly is relatively similar sensitivity but with a higher impedance), then the lcd 2 classic with a similar sensitivity but lower impedance, and then the aeon 2 actually requires the most power to get going with a much lower sensitivity (despite the low impedance)
In the real world, the ananda requires more power than it would seem at a glance, but again if you can get like a reasonable amount of power it’s going to sound solid (similar to how the lcd 2c would). The elex while pretty efficient, is very demanding on the quality of power to where it becomes very amp picky for what it sounds good with. The aeon 2 also requires a fair bit of power and current, while a decent demand on quality of power
So basically what I’m saying is that you would want to spend more on an amp for the elex and aeon than you would for a lcd2c or ananda
If you pick a warmer thicker toned amp I think you could be fine as long as tonal density isn’t your main goal