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
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
This drove up his cost from 1 to 3
Blade Splicer is the easy one
Enchantment Color tag templates(None) Fable of the Mirror-Breaker (As this Saga enters and after your draw step, add a lore counter.) I Create a 2/2 red Goblin Shaman creature token with "Whenever this token attacks, create a Treasure token." II You may discard up to two cards
If you're going to use it, spells that can meet the condition in the 4-mana range are essential