These cards have the same play mechanics as their non-serialized versions
To use Radiant Lotus properly, you need to set up your board in a way that will allow you to generate an absurd amount of mana
As they try to cast a spell, it will get exiled under Knowledge Pool, and when they try to cast a free spell from under the Pool, Lavinia counters it
Summon: Bahamut will destroy two problematic nonland permanents from an opponent, draw two cards, bash for a bunch of damage and can close the game with its final chapter
This allows you to play it before combat and trade off bigger creatures, growing the Pelt Collector
Gales Redirection probably ends up in more Commander Cubes than 1v1 environments, but its definitely a powerful option if you can stomach the variance of a d20