Typically, the hardest part of this process is balancing the card to be fun but not broken, like a card that wins the game if it hits the opponent
Each half is amazing here
Combine the Shorecrashers pump abilities with Nykthoss mana generation (which Shorecrasher buffs majorly) with the Anthems, and it is very possible to have Shorecrasher turn into a 9/1 or even bigger at times Which sure is nice with Thassa, God of the Seas unblockable ability
Okay, but not that impressive, and by this happening on damage, you miss being able to use this to clear blockers
That's good value over two bodies, but you don't get the other card for free, so the value if getting a 4/2 haste without flying is significantly less than the version with myriad
The easiest way to help is having things that change be square statsthat is, their power and toughness are equaland have the changes also be square stat changes