I would play it with no starter.
Why not?
Kingdra has a difference to almost any other T2 deck - it needs only 1 energy to do good damage.
Most T2 decks work like that:
T1 - attach energy, do some minor attack
T2 - evolve, attach energy, attack
(if you don't get out T2, you'll get into a disadventage)
Kingdra can be played this way:
T1 - attach energy to starter, do setup attack (Pachirisu, Phione, Lapras whatever)
T2 - Rare Candy to Kingdra (or evolve to Seadra), attach energy, reatreat, attack
(if you don't get out T2, just take one more turn with your starter)
No reason to start with Horsea, because you won't miss the energy attachment to your mainhitter. Of course there is the chance to get T1 Rare Candy Kingdra, but this will happen very rarely und is nothing you rely to.
btw - no Blissey!
It takes your energy from discard pile, but you want to have it there for the second attack.
There is absolutely no synergy between Blissey and Kingdra.