This deck is primarily designed for going first, as the general strategy is to disrupt and out-resource the opponent using the ridiculous recovery/resource generation of Eldlich combined with the durability and power of Mayakashi. Provided you have the Golden Lord out on the field, the Eldlixer quick-play spell and trap become quick-effect reborns for your Mayakashi synchros to provide additional disruption and recover from positions of disadvantage remarkably easy. Eldlixer of Black Awakening can also serve as an additional method of getting out Hajun, allowing you to access your synchro ladder turn 3 relatively easily if you failed to do so on turn 1. Dakki/Yuki-Musume provide recurring tribute fodder for the Everglorious Golden Land, and the deck is capable of easily getting out the Mayakashi synchros using either Hajun or Dakki + the Golden Land trap-monsters (who are level 5, excluding Guardian). Mayakashi Winter also serves as both a nice consistency booster with its draw effect and as good fodder for the Golden Lord's revival effect. Eldlich and Mayakashi complement each other extremely well, as Eldlich allows you to easily control the state of the game while the Mayakashi synchros enable you to output massive damage when presented with openings, compared to pure Eldlich's normally mediocre damage output.
For the side deck, most choices are cards that aid in going second as this deck is overall weak to disruption early on and struggles to start up against established boards. I have additionally included a package of Generaider cards as they are a solid addition to the deck if you choose to play them (though they are main deck material). If you do decide to run the Generaider "engine", the ratios of Golden Land and Eldlixer cards should be adjusted slightly to provide room (cut Conquistador down to 2, Guardian down to 1, and Eldlixer of White Fate down to 2/1, by preference. Other cards to consider cutting for room are Ash Blossom, Dakki to 1, Yuki-Musume to 2/1, or Mayakashi Winter to 1). While Hela does provide good additional quick-effect revival, she is by no means essential to the deck and can often be somewhat clunky and unnecessary as the Eldlixer cards generally have the same utility while being far more consistent, thus I would suggest that you try out the Generaider cards and see if you like them before fully committing to the idea.