ooooh, I read this completely wrong first time. So "Discard a card" is the cost. I was trying to figure out how that worked as a cretaure ability. (ETB effect? On damage?)

Why not re-use the splice terminology, instead of enhance?

Also, 'storm' is kinda already a keyword, and power sounds like it should be... so it could do with renaming.

Yeah, I had to read this card multiple times to figure out what was going on... and I'm still not sure. Because I'm not sure if you could discard this card as part of the cost, if that's what you wanted to do.

I like what's going on here, but there is a lot to process, and I don't really feel like it pays off. Personally, I think you're best getting rid of the word 'Enhance' and just turning this into:

"When a creature enters the battlefield, you may reveal this card from your hand. If you do, you may discard a card. If you discard a card, target creature gains haste until end of turn."

Which help simplify what's going on here. The double "If you do" feels silly, I know. But that's the type of hoop that this card is setting up.

Thanks to both of you for your comments. I am aware that Enhance is kinda confusing. Hence the reason why I am unsure if I want to use it. If you want a better idea of what Enhance can do, you may want to look at Shadow Reaper too.

Also, if you compare the writing of this and splice, you will see they are functionally the same except that this is uEoT since Enhance is effective on a permanent and not a spell.