In terms of playability, it is absolutely going to show up in multiple decks, particularly right after set release
If you pay four mana for the kicker, everyone else has to mill half their library rounded up instead
While Caw-Blade was merely historically good before the printing of Batterskull, this was enough to elevate it to God-tier
No, instead, they played Demonic Consultation, with the primary target being the single copy of Channel
This change does not impact Limited boosters
You can set up these triggers however you like, so if you want to have a few token Merfolk you have lying around try and power through your lands you can, while giving Hakbal and your other creatures the +1/+1 counter when you explore a nonland card