Hey! Bestow is a good mechanic!
You are right CML about accessibility, although often it is difficult for players to follow cube designers down the rabbit-hole, especially with regards to riptide-cubes (doubly so if the understanding of cube is derived from Grim Monolith cubes). I mean, if you open a pack and see one of the supporting cards for a theme, then it is very difficult to reverse engineer the design principles. How do you leap from a
Path of Bravery to the understanding of a life gain theme based upon maximising the number of life-gain triggers, while caring very little about the actual value? Sometimes it is good for newish players to just be able to build a reasonably simple deck based upon Magic principles, as opposed the cards that are exceptions to the Magical norm with which we tend to stuff our Cubes. How do you build this into a Cube? I don't know, and I am not sure if I want to know, because then I might be tempted to take out all of my 'fun' cards.
Gyah! I don't know if I really have a point. At one point there it was 'Accessibility be damned!', but I realise that is not a very healthy attitude to have, and I recall a recent 'split-card cube' that nearly made my brain explode, let alone the brain of someone new to the idea of cubing. Maybe it is take Magic principles about deck roles and the roles of certain cards within those decks and replicate that, to ensure that someone new to your cube understands that 'If I am looking to play control, I probably want to value these sweepers and counter-magic pretty highly...'. Then we can layer all sorts of fun interactions over the top of that, which can serve as wonderful 'Oh! I see the cool things this can do!'. Anchor cards seem important for this. Pushing this too hard just makes the cube unintuitive all over again...