This can cripple a lot of decks while leaving yours untouched if youre relying on anthem effects to do the heavy lifting
You can utilize Xenagos to great effect by letting your biggest creatures swing on out at an opponent as soon as they come into play, being particaully good when used with creatures that have strong attack triggers or ones that will undoubtedly be targeted immediately by your opponents
Don't forget that if your life is at 22 or 21, you can target yourself and have an indestructible Bane
Plus, whenever one or more Rogues you control deal damage to a player, that players mills one card for every one damage they were dealt, and if they mill a Creature card during that process, you get to draw a card
Since it wasn't renowned when it dealt combat damage, Aragorn, Hornburg Hero's last ability won't trigger, and you won't double the number of +1/+1 counters on it
Forever, or at least until someone removes the enchantment since its a huge threat