Keruga, the Macrosage Keruga, the Macrosage has companion
Circling back to TAUC costs, you could argue its actually even closer to free than other alternate costs: life points and cards in hand are expendable resources, and (at least for drawing cards) somewhat expensive to replenish
If you want a more devious way to build Kelsien, slap on him a Thornbite Staff, which lets you untap Kelsien each time a creature goes to the graveyard
It has four Strength and six Willpower, plus the ability to quest for three lore
The story of Duskmourn: House of Horror has been published in its entirety, with a main story focusing on rescuing Nashi and side stories that showcase other parts of the House
Later in the game you should be able to pay the escape cost, especially if you have any amount of self-mill (dredge, Im looking at you)