Very few cards from Foundations peeked my interest. I skipped updating the cube for that set. In this update I'm adding a new cheat effect and swapping some green cards.

Consecrated Sphinx -> Flash
A powerful and iconic cheat effect. The creature needs a good death or ETB trigger (Worldspine Wurm, Woodfall Primus, etc). However if achieved, being only 2 mana makes this a very fast cheat effect. Also tutorable with Spellseeker. Consecrated Sphinx is powerful when it works, but blue has other powerful 6 drops and snowball cards.

Garruk Relentless -> Scythecat Cub
This version of Garruk is showing its age. Last draft someone played Garruk and it was very underwhelming. I'm trying out the cub as other cube creators have been impressed with Bristly Bill, Spine Sower. They're very similar but I like the cub slightly more.

Biogenic Ooze -> Elder Gargaroth
Biogenic Ooze is a pet card of mine. I liked using it with things that care about tokens, but it's not the most individually powerful card. I want a big generically powerful 5 drop to go along with the more specialized ones like Deranged Hermit and Plow Under. Elder Gargaroth is certainly a big dumb creature, very painful to play against as aggro.

Titan of Industry -> Vaultborn Tyrant
Very powerful fatty. Works with most cheat effects, including the newly added Flash.
I like Titan but Vaultborn does seem more powerful and their abilities do have some overlap.

Vorinclex, Monstrous Raider -> Nissa, Ascended Animist
I've been wanting to try Nissa for a while. Fits into your curve as a 5, 6, or 7 drop. Demands an immediate answer or will flood the board with huge tokens. Vorinclex was mostly just a 6/6 trample haste. That is good, but wasn't very exciting as a ramp or cheat payoff.