Having that be an end step trigger is a bit annoying, but you can then cast Magic 's OG combo piece, Channel, to turn any amount of life into colorless mana, just in case you have some spare Eldrazi Titan in your hand
This in turn can provide useful information as to what is in their hand based on how they play around the card
Mono-Blue Commander decks are renowned for drawing lots of cards, protecting combos, milling libraries, cheating in Artifacts, and somehow still having the audacity to say they're just a casual mono-color deck
Any card with a different colored expansion symbol (such as the purple expansion symbols from the Time Spiral timeshifted sheet) is treated as a special rarity
There are a few cards hither and yon that allow some incidentally in blue (Turn into a Pumpkin), while red is all about cant gain life as the inverse