The card can completely turn the tide of a late-game stale-mate by granting massive stat boosts and extra lore-gathering potential to lesser allies
Decks like Krenko, Mob BossKrenko, Mob Boss, Isshin, Two Heavens as OneIsshin, Two Heavens as One, and Etali, Primal StormEtali, Primal Storm would absolutely love this card, as it enables them to do "their thing" the turn they come down
If an effect instructs you to create a token and then do something to "it", replacement effects like Doubling Season change that "it" to mean "each token created this way," not just the first one
Now, nobody in their right mind would suggest that cards like Thalia, Heretic Cathar or Urabrask the Hidden are in the same league as the above cards, because theyre not
Regardless, my point is that Xenagos might be reason enough to play a second color