Typically , similar cards in similar card games with the permament increase in hand size tend to be extremely powerfull. This card even draws you cards and is attached to a body all at a fair cost package. With that being said hearthstone is defined by archetypes at the current meta. And weak or dominant archetypes. If handlock or control lock is a thing again this card pushes the barrier to meta defining else its a just pretty strong card without a certain "home" to shine.
Works really well with the Warlock Dragon package since you already want to be playing Twilight Drake. Legitimately all Drakolock needs is like literally any 1 or 2 more decent dragons just to make sure your Nether Breath and Crazed Nether Drakes actually trigger. You don’t need that many more dragons since you’re going to be drawing so many cards.
Not everyone may remember this but there was a period after Blackrock, just before the Grand Tournament where there was exactly one good Dragon deck and it was a Dragon Warlock where you played Blackwing Corruptor, Azure Drake, Twilight Drake, and Malygos as your entire dragon package and you would Thaurissan your Soulfires and Dark Bombs and kill them with Malygos. It was awesome.