It can spend more than three energy if you have it handy, scaling up to bigger threats with proper planning
Both Lord of Atlantis and Master of the Pearl Trident do very similar things, helping to both buff the rest of your squad and provide evasion to your team, so long as your opponent controls an Island
It's a personal choice to run this over something like Crux of Fate, Life's Finale or Decree of Pain but my reasoning is that instant speed board wipes in this deck give us a huge edge over the opposition
Being able to cast and recur Lotus PetalLotus Petal from the graveyard to build up a massive storm count and generate copious amounts of mana is the immediate thought
Supporting a local game store means you have a place to buy Lorcana, trade cards, and play in Lorcana League
If at least one part of the merged creature got through it's summoning sickness, then it can attack or for abilities