Mulligans
General Mulligans
In general, Mulligan for your minions (most importantly Elven Minstrel), other important cards will come with the big amount of card draw this deck has.
Aggro Mulligans
Against Aggro, try to get as much removal as you can, you can't combo if you're dead after all
Midrange Mulligans
Against Midrange, Vanish and Sap can let you survive long enough to pull of a combo.
Combo Mulligans
Same thing as Control, Malygos Druids tend to get a lot of armour, make sure you can deal with it.
Control Mulligans
Against Control, try to get an as high possible dmg combo as possible, since they tend to get quite some armour.
Let me begin by saying that this deck is not my idea, but I saw it in a video of Chump, who had it from the r/CompetitiveHearthstone subreddit. Also, I’m by far not a competitive or great Hearthstone player and I haven’t posted many decks or guides or whatever, so always use your own brain when reading guides and coping decks.
General Info
On to the matter at hand; Kobold Illusionist Malygos Combo Rogue, as the name suggests, you use Kobald Illusionist to cheat out Malygos and then kill them with spells. You can pull off a 35 damage combo as soon as turn 7. With Preparation plus Necrium Vial you can summon 4 Malygos and deal up to 88 damage (20 spell damage on 2 Razorpetal and 2 Sinister Strike ). To get the combo (as soon as turn 7) here is what you need to do; find Kobold Illusionist and Malygos and have them as only minions in your hand. Next, have at least 1 sinister strike and 2 Razorpetals in your hand. Have a Necrium Blade equipped with 1 durability left, lastly, have a Backstab in hand. Play Kobalt Illusionist, break your weapon (preferably on your opponents face), this summons 1 Malygos, then Backstab your Kobalt Illusionist for 1 more Malygos. Last step: kill your opponent to death with your 13 damage Sinister Strike and two 11 damage Razorpetals. Depending on the opponents life total, you need more or less spells.
Mulligan
You basically want your minions in your opening hand, since they either are the combo or draw the combo. Depending on the matchup, you can keep other cards, like Fan of Knives against the pesky Odd Paladins or Sap against Hunter. Not much more to talk about in the Mulligan.
Substitutions
You can remove almost any spell of the deck and substitute it for another spell of choice. As long as there are no minions added or removed, since with 2 Elven Minstrel , you draw exactly all minion combo pieces you need. Valeera the Hollow is not required by any means, but she can be a lifesaver in some cases. You can substitute in more removal or maybe even Rogue secrets (But that might be a doubtable decision).
Other Tips
Keep track of your hand size, since you can quickly fill up your hand with cards like Razorpetal Volley and Elven Minstel. Burning your Malygos means an instant concede even faster than a warlock would when burning his DK. (I burned Malygos once because Roll the Bones drew a deathrattle card).
Get face damage in when possible, since the more face damage you do, the less burn spells you need to kill your opponent.
Don’t forget to empty your hand of other minions before setting the combo off, it would be a shame if your Kobold Illusionist would pull out a Cavern Shinyfinder.
Don’t make the mistake to mulligan for Necrium Blade, you’ll get it of Cavern Shinyfinder anyways
Tempo and aggro decks most likely wreck you like a baseball bat would do to a piƱata, so don’t forget to give them that BM double well played if you nevertheless kill them. (Nah, never BM guys, you need good karma to draw well with this deck)
I hope I didn’t forget anything important, please leave your constructive comments below and I hope you’ll wreck some of the obviously inferior Malygos Druid on ladder (or any druid for that manner).
Greetings and may RNGesus be with you,
Z