Even so, the odds of pulling Thought Vessel in a deck of 99 (excluding the commander, who goes into the command zone) are slim, so adding Reliquary Tower can increase your odds of having a limitless hand size
You can do that when you need early game ramp and it can even be used for something like reanimator strategies as you can cycle it, make a token, and use that token as, say, Dread Return fodder
It's basically Mana Confluence, and in many scenarios, it's even better since you can generate colorless mana without pain
Saheeli, Filigree Master Locking the cost reduction on Saheeli, Filigree Master behind this planeswalkers ultimate makes achieving it rather dicey, but the low ultimate cost makes up for it
When all the stars align for a perfect progression, however, Sapphire/Steel can be hard for any opponent to stand against