Indestructible (Effects that say "destroy" don't destroy that permanent. An indestructible creature can't be destroyed by damage.)
As long as your devotion to red and green (Each or in the mana costs of permanents you control counts towards your devotion to red and green.) is less than seven, Xenagos isn't a creature.
At the beginning of combat on your turn, another target creature you control gains haste (This creature can attack, and as soon as it comes under your control.) and gets +X/+X until end of turn, where X is that creature's power.