This can save a lot of mana, even though you can only activate this ability as a sorcery
Ideally, I would not leave a Dream Trawler post board since its weak against both Shatter the Sky and counters but I just dont have anything better
Players who put in overtime at work to be able to afford that last dual land, long-time players who considered their collection to be something of a nest egg, people who convinced their spouses that these Reserved List cards were a good investment as well as a fun weekend hobby
Early turns generate cards from cheap spells opponents cant afford to tax, while equipment and pump effects follow, increasing the tax rate to prohibitive levels
On the other hand, without being instant, it would be underpowered, so it needs that addition to make it playable, except that it really isnt
Most of those keywords will have "When", "Whenever", or "At" in their reminder texts