Yeah, Deny is broken. The way you can reserve earlier turns' mana for Deny ammo makes it an incredibly strong card. It's a meta-defining card and if you play Ionia without running Deny you're voluntarily sapping a ton of power from your deck. It's just too versatile against way too many decks. There's not a deck out there that hoards most of its spell power on burst spells...that literally just does not exist.
The argument for % statistics on drawing Deny is also...mind boggling. First, if you have played any other card game before, you realize that those odds are actually INCREDIBLY good. In Hearthstone your deck size was 30, but you were limited to 2 copies of each card. In Magic your deck size is 60 (mostly) and you are limited to 4 copies of each. In Runeterra, more often than not you will find what you are looking for in your initial mulligan or first few draws. Second, you can literally say that about any card. You could run 3 cards that are burst spells "Win the game." and point out the % statistics and yell, "Look at the percentages!!" Point being: just because a card has a low draw percentage doesn't mean the card is not incredibly strong. (This doesn't apply to Deny, but for example you could only have 1 copy of Legendary cards in each deck in Hearthstone. That didn't make some of the OP Legendaries any less OP.) Not to mention--you literally don't want Deny in your early opener. The fact that you may draw Deny later rather than earlier is a good thing.
The state of the game right now is to not run high-cost high-swing cards, unless you want to lose every game vs. Ionia. Vengeance, Ruination, Judgement, etc. all just quake in fear of Deny. (Which is actually kind of funny thematically when you consider Shadow Isles quaking in fear of Ionia...)
