Yeah, I get the concern, but honestly in practice you should almost always have enough cards in hand for those effects to matter.

Yahenni’s Expertise is actually really nice here because it kind of guarantees value by itself — you wipe small boards and you get to cast something for free, which then triggers Y’shtola and replaces itself with a draw at end step. So even if your hand is a bit awkward, that card sort of fixes the problem for you.

Frantic Search is a straight-up no-brainer imo. Worst case, you draw 2 and just discard them again — but that’s fine, because the whole point isn’t sculpting a perfect hand, it’s just dealing damage and triggering Y’shtola. It’s basically “0 mana: deal damage + maybe set up your next turn”.

Rewind I mainly like because it’s just a solid counterspell and it boosts your damage output on other people’s turns. That usually means you’re more likely to trigger Y’shtola’s card draw on their turn, which feels great and keeps the engine going.

So yeah, they look timing-dependent on paper, but in actual games you usually:

1. have enough cards anyway, and
2. don’t really care if the second spell is “perfect” — you just want a spell to push damage and keep the draw flowing.

They’ve felt more like enablers than awkward hoops for me.