The effect of is not a problem, but in many cases, the effect of the monster you want to negate has already been activated before you can activate it, and I remember that this effect affected the outcome of the game
I still remember when Jwari Shapeshifter was previewed and thinking, "Now, there's a card that I want to play in Limited Allies." (I would go on to draft the most ridiculous Ally mill deck in my Magic career
3 Terror Tide Tide Is High But I'm Holding On Board wipes are among the most divisive cards in Magic, in the Commander format especially, so its nice to see one that actually demands a specific playstyle in order to be useful
Her Trainer Class is Top Champion and is known for using Espathra, Gogoat, Veluza, Avalugg, Kimgambit, and Glimmora, which shows a great variety in the Pokmon type that she is using
Like Transgress it has always been a backup option when the better spells are gone but there really isn't that much redundancy in "targetted" one mana discard
Cost aside, the other big problems with cards like Omniscience is their lack of immediate impact and the fact that they taper off once you run out of cards in hand
