Riku is still very playable, despite being popular for years
A creature with Protection from a quality, let's say a colour for simplicity, can't be targeted by spells and abilities of that colour (like Shroud, that's regardless of who controls them)
Training is a new keyword that works like a reverse mentor mechanic
Presumably for these players, the bunny artwork is part of the attraction
The True Draco monster cards used in this deck are able to search the deck for themselves, as well as other True Draco Continuous Spells and Traps, giving players access to whatever they need to respond to their current situation
As for closing out games, there are a few options