You can use eternity on opponents creatures. I would add in Sobras. But use eternity for cc instead of rain of fire. If you use eternity also on opponents creatures you then have more turns you have to reverse time your rol. The only time ive been smart to reverse time enemy creatures was in pvp2 vsing a dune scorp chaos power blessing deck. Also the title says against plat, so I would definitely want more cards in the deck then 32. Plat decks usually have 70-90. And the deck out plat decks can be pretty nasty and should probably be the decks auto quit.
We were getting highly offtopic; the deck we are talking about has nothing to do with the one in the op besides that it pretends to be a perfect defense; its not feasible against plat; its probably not even effective anywhere, so we probably should just stop talking about it. Anyway using eternity on the opponents creatures effectively increases the opponents deck size, which is basically the most stupid thing you can do in a full stall unless you have tons of continuos healing (which you dont).
By adding dune scorp + buff you have an alternative to win, however you will get the most frustrating draws ever, because you mostly only have just one copy of each important card.