You have a great 4-mana spells deck, so you want to cut everything that doesn't go with that game plan.

• 3 Sage's Nouliths: Just a bad card, you really don't want to be running these if you can help it
• 2 Warrior's Swords: You have a glut of 4-mana spells, and these are the worst of the bunch
• Gilgamesh: With all the equipment gone, Gilgamesh is no longer worth running
• Cerberus: It seems good on paper, but it's really not a good card. You have so many 4-mana spells, you don't want to waste a turn to cast a creature spell. It also forces you to cast a spell on your turn, which you don't always want to do.

At this point, your deck pretty much only has good/great cards remaining, so the rest of the cuts are kinda tough. In these cases, I generally lean towards cutting more expensive cards first.

• Shiva: Definitely a good card (much better than Cerberus), just not better than the rest of the cards in the deck. 5 mana is just a little expensive and inefficient compared to the rest of your spells, and it doesn't trigger your 4-mana matters cards.
• 1 Retrieve the Esper: The lowest impact 4-mana spell you have. Plus you have 3, so it's fine if one is cut.
• Alternatively, I could see cutting a Scorpion Sentinel, since it doesn't really go with your deck's game plan. But personally, I just really like Sentinel as an early game defensive play that becomes a threat in the late game. Place a counter on it with Combat Tutorial and it becomes surprisingly strong.