By repeatedly blinking Alena, Kessig Trapper with Emiel the Blessed, you reset Alena each time she returns so she can tap for a massive burst of red mana based on her own power. Tuktuk Rubblefort ensures that this entire engine can get off the ground the moment it hits the board by granting haste to your creatures, allowing Alena to tap immediately without waiting around for summoning sickness. Once the mana starts flowing, Emiel's ability keeps the loop self-sustaining while simultaneously triggering any other enters-the-battlefield effects you might have.