Out:
Springleaf Drum - Was a dumb idea after all.
Everflowing Chalice - Replaced with Lotus Bloom
Padeem, Consul of Innovation - Theoretically a better phyrexian arena with a built-in protection for artifacts, but usually failed to stick until next turn in practice. Removed in favor of wear // tear.
Solemn Simulacrum - Fetching a basic land is not crucial, plus not that good of a blocker. Replaced with Baleful Strix

In:
Wear // Tear - Good artifact/enchantment removal.
Lotus Bloom - Can be reshaped into play, good in the opening hand
Prophetic Prism - Source of colored mana for the scepter combo, replaces itself.
Baleful Strix - Replaces itself, a decent blocker. Testing in place of Solemn Simulacrum