What's the point of Xaxos' power in Aeon's end?
Context, Cost, and Timing are the definition of Xaxos power  

Xaxos power is amazing: its ability to manipulate the turn order deck can save the game from being lost or set up some really amazing combos, it is one of the 'cheapest' powers in the game, and it can be extremely useful when combined with certain other mages.

Lets look at each part of his power:  


Cost of 5: this is pretty much normal, and powers that only cost 4 are usually weaker than the ones that cost 5+.  
Activate during any player's main phase: You don't have to activate this on your turn which means it doesn't matter who goes first in a round, you can immediately set up the entire round to go the way you want it to go. More on this in a minute but since a lot of powers are restricted to your own main phase, this definitely gives this power an advantage.
Allies collectively gain 4 charges: This effectively refunds almost the entire cost of your ability to your team, making this one of the most efficient powers in the game. While there are a lot of cards and abilities that grant charges to 'yourself or an ally',  granting that charge to an ally means you don't get to use your own power as often. Not so if you're granting that charge to Xaxos, since he refunds those charges back to the other players when his ability triggers. In most games I play with him, the Xaxos rarely generates more than 1 charge for himself but he still ends every round with full charges, refunding them to the rest of the team at the start of the following round.  
Reveal the turn order deck and return the revealed cards in any order: This can be used in two ways: control the nemesis turns or set up player combos (or both). Controlling exactly when the nemesis turns trigger can allow your team to knock out a critical bad guy before he destroys someone, or it can allow you to set up a teammate with just the right discard trigger to get rid of a nasty power card before it goes off, or even just break up the nemesis turns so he doesn't go back-to-back and toss out (and immediately trigger) a strong Power 1 card with no chance for your team to respond to it. Setting up player combos can also be very powerful and there's too many combos for me to list them all (e.g. letting the mage who just prepped a full load of powerful spells go before the nemesis forces everyone to discard prepped spells), but Xaxos' own unique starting spell benefits from this too by allowing you to set up a Player turn order card immediately after your own and amp up the power of your spell.


There are probably a ton of other examples of how this is useful, but to me Xaxos is definitely a strong contender for a position at the table in almost any game of Aeon's End I play.