Thomas Neilson
If there's any archetype I could wax poetic about endless, it's this one, and with two Castiel lists making top 8 in the recent War Of Attrition #2, I thought it'd be helpful to compile a shorter list of tips on playing this divine powerhouse of an archetype. Lost Messiah Tempo is at it's base a burn deck, looking to turn an early board advantage into a quick burn kill on veil pierce thanks to Castiel's Special Ability: Oblation. In terms of surviving early, you're looking for a few key cards to help you start drawing cards, especially Chaos Divine Reconnaissance, Help From The Chaos Divine, and Kabshiel's Favours For The Seraphim. If you don't have some of these pieces, Acceleration Into The Chaos Divine and your card draw Warriors can help to find them.
Early Tips & Playlines
With your Guardians post-mulligan ability, Sigrid, Avenger Of The Lost Messiah, you'll be looking for the same line 99% of the time. Eradicating Oath To The Lost Messiah allows you to tutor up Empyrean Empire Of The Lost Messiah as a strong Holy Counter generator. If Oath is in your opening hand, you can eradicate Acceleration Into The Chaos Divine to eradicate the Oath in your hand.
Speaking of Empire, it's one of your strongest tools for card selection, putting Warriors in play, removing problematic cards, and keeping your boardstate safe. That being said, sometimes it's better to save the AP for other important cards like Bow Of The Archangel and Radiant Orb Of Divine Light.
Bow Of The Archangel is one of the strongest cards to have set going into your turn 3 kill, being able to knock out 3 cards at the end of your opponent's turn. In combination with Freelia, this can completely shut down a backline.
Late Tips & Playlines
Lost Messiah Corrupt-Sword, Freelia is a key piece for the deck with the (Rift) ability to destroy opposing player's fortified cards, especially off of Veil Pierce. If you get the chance, this is easily the best card to shuffle back into your deck with Mists From The Fata Morgana or any other effect.
Your best way to build up Holy Counters for your Oblation kill is with Halo Of The Lost Messiah, each one you eradicate lets you dump up to 15 Holy Counters onto your Warriors, so it's worth saving them for your turn 3.