This is incredibly powerful in conjunction with the right cards, as it allows you to really accelerate the resources you have available and stay a step ahead of your opponent all the way
Since two of my dearest games have united in such spectacular fashion, this is a dream come true for me, as someone who likes to lean toward the Vorthos side of MTG
But Sidar comes in clutch there as well with his damage trigger, not to mention other recursion cards like Haakon, Stromgald ScourgeHaakon, Stromgald Scourge and Knights ChargeKnights Charge
Once you do complete the Undercity, Rilsa gives one of your creature's a massive buff that makes it rewarding whether it is blocked or not in terms of killing creatures or dealing massive damage
Spend the early turns tapping mana dorks and passively buffing your team, until eventually you can start to swing wide with deathtouch