Very strong against the current aggro meta. The worst matchup is probably Tickatus warlock, but not unwinnable (mulligan heavily for Galakrond/ Kronx for that matchup).
Update 1: Switched Shadow Word: Death for Gift of Luminance. With all the discount cards, it is easily possible to play the card with Catrina Muerte or Blood of G'huun in the same turn. Plus, if there is already a card on board, Grave Rune and Gift of Luminance combo is nutty.
Keep Palm Reading and Insight for all matchups, this card combo is very strong. Archmage Vargoth is also generally good to keep too. Below is matchup specific cards to keep for each class, ranked roughly in order of importance:
- Demon hunter (Great): Breath of the Infinite, Holy Nova, Penance, Renew, Hecklebot
- Paladin (Great): Convincing Infiltrator, Penance, Breath of the Infinite
- Hunter (Even): Penance, Breath of the Infinite, Renew, Convincing Infiltrator
- Shaman (Good): Penance, Convincing Infiltrator, Breath of the Infinite, Holy Nova, Soul Mirror
- Mage (Even/Good): Penance, Breath of the Infinite, Renew, Convincing Infiltrator
- Warrior (Unlosable): Hecklebot, Galakrond, the Unspeakable, Plague of Death
- Druid (Good): Convincing Infiltrator, Shadow Word: Ruin, Soul Mirror, Plague of Death
- Priest (Good): Galakrond, the Unspeakable
- Rogue (Good): Breath of the Infinite, Holy Nova, Penance, Renew, Convincing Infiltrator
- Warlock (Even, assuming Tickatus): Galakrond, the Unspeakable, Hecklebot, Convincing Infiltrator
Big tip against ETC warrior: If you didn't pull their combo with Hecklebot and you think they might have the full combo in hand, just make sure to never play minions with health total above 7 (lower is better). Their combo requires at least 7 health of minions on board to do the OTK. Just keep passing turns until they die to fatigue, and if they commit you can just clear with Plague of Death. It can also be good to not play Galakrond, the Unspeakable in this case, since the heal hero power would be more useful here.