Spellthief's Edge needs a better upgrade...

Spellthief's edge is a pretty good item, but the fact that it doesn't upgrade into a really strong item like Talisman is pretty disappointing. My thoughts are that it's second tier upgrade should have something to do with mana regeneration and poke, to differentiate it from the Coin second tier. Like the old Wit's End that used to steal mana. If that isn't a mechanic that works well in the current game, at least mana regen on spell/attack of some kind would be cool. The third tier also needs a big upgrade. Thoughts?