Blade Splicer is the easy one
That first ability resembles the shenanigans you can get up to with Dargo, the Shipwrecker, so in the right deck, you can cast it for two mana, attack for seven (that can only be blocked by legendary creatures), and then sacrifice it to destroy an annoying artifact or creature
In the commander format, since everything beyond lands can only be included once, thats a handy tool to have in your arsenal
Its design highlights the growing use of creature tokens as a fodder for other cards
This drove up his cost from 1 to 3
Currently it stands at about $20, but it may go up if it proves to be better than its predecessor Thassa, God of the Sea from the original Theros set