Kraken Hatchling is a good blocker, but offers nothing else.
Embodiment of Spring on the other hand is a good blocker with early mana ramp.
Whelming Wave is too expensive to mesh with
Kraken Hatchling.
Dragon's Eye Savants would be great if more expensive. Especially if you had counter spells to use and needed info.
Sidisi's Faithful is good and cheap for stalling and you have a sacrificial lamb with your other one blue mana creature. It also works with
Whelming Wave. You can use it on itself if you run out of expendable creatures.