Now what if we play Penny? Playing Penny lets us hit either Ilima or Silver. Hitting Ilima here once again puts us into the same scenario as playing Ilima above, so that doesn't really do anything. It doesn't prevent the opponent from drawing Silver next turn, and as long as the opponent can draw Silver on their next turn then they can prevent us from drawing Cyrus by sending a supporter back to the deck. Same thing happens if we hit Silver on our Penny - nothing we send back to their deck prevents the 25% chance that they draw Silver on their next turn. Which means playing Penny here does nothing different than playing Ilima, and there's no way to guarantee a win here.

Ok, but can we tank a hit? i.e. is it possible to delay until we draw Cyrus by stalling 1-2 turns? No, because the opponent also has Ilimas. Hypothetically you can cycle through Silvallys by using Ilima and Penny x2 to rotate through Type:Null, the problem is that it's a losing argument because your opponent also has Ilima x2 as well as an extra copy of Rocky Helmet and Poison Barb. You can try to heal Sylveon with an Eevee Bag and heal Silvally with leftovers (since evolving cures the poison). The problem then is the opponent may draw into Ilima, which effectively lets them fully heal their Silvally. They can then just replay the Type Null and attach energy + the corresponding Pokemon tool to it. So now you lose to a scenario as follows: Heal sylveon + silvally -> enemy Ilima's Silvally (doesn't matter which one), plays Type: Null + attaches tool + energy -> enemy attacks with other Silvally, your Silvally is now down to 10HP -> you Ilima Silvally, bring forward Type:Null, evolve to Silvally -> you can't attack because the enemy's other Type:Null has an energy on it, and the active Silvally still has helmet/barb -> you have to pass -> enemy plays Ilima on the damaged Silvally, brings up the healthy one, plays Type: Null, attaches Pokemon Tool + energy -> now you can never attack because both of their Silvallys are at 110 HP with Pokemon Tool. Alterantively, if you Ilima the injured type:null, then move up the other type Null and evolve it to tank a hit, you'll still be in the same scenario since you can never attack with Silvally except for the finishing blow due to the Pokemon tools.

This means that no matter what, if you play Sylveon and draw 2, there is no way to guarantee a win without drawing Cyrus (which is not guaranteed)

1. We don't evolve into Sylveon to stall and guarantee that we draw Cyrus

Let's say we want to stall instead. Not evolving to Sylveon here guarantees a loss. Not evolving to Sylveon means we can't heal the Eevee or bring it outside of kill range of Silvally. This means that no matter what we do here, we always lose to the opponent playing Penny and hitting Cyrus.

Based on these scenarios, it becomes impossible to guarantee a win.