This is my take of Xenan Midrange, a deck that I am very fond of. I like Xenan because it allows you to play with big Time fatties while still having access to Shadow's removal and busted cards like
Exploit and
Twinned Spiteling.
A few notes on specific cards:
Waystone Ignitor - this isn't always the strongest card, but it gives you a very versatile 1 drop. All three modes can be useful at different times.
Vara, Vengeance-Seeker - I've seen quite a few midrange Xenan decks cut this card, but to me it is still one of the best 4 drops in the game. Killing Aegis is great, and lifesteal can be crucial against aggressive decks.
Xumucan, the Surveyor - I think this card is criminally underplayed. It's basically bigger than any other 5 drop, and Ambush is so good - not only for ambushing enemy units, but also to dodge sweepers. Warp is also surprisingly strong, often giving you direct card advantage.
Touvon, Skybreak Giant - my absolute favorite Time 6 drop. Has Ambush, draws you cards, has overwhelm - what else do you want?
Sea of Teeth - I se this not only to kill attachments, but sometimes just to use the Teeth to clear out a bunch of enemy low health units.
Is this the best deck? Probably not. But it got me to Masters, and if you like big Time units it's a blast to play.