These formats also allow a host of other cards from select expansions and releases (including those promotional cards that came free in McDonalds Happy Meals for a while), which are the same for Pokmon TCG and TCGO, and can be found on the Pokmon website
Legendary Creature - Berserker Dwarf Spark Double You may have this creature enter as a copy of a creature or planeswalker you control, except it enters with an additional +1/+1 counter on it if it's a creature, it enters with an additional loyalty counter on it if it's a planeswalker, and it isn't legendary
There can only be 1 "Malefic" monster on the field
And again, you dont even have to plan for the most likely way to see more than half your deck in Standard, which is What if Soaring Thought-Thief mills my search targets? But five cards is a lot of sideboard space to use these days
Kangaskhan does have an RNG built into its Dizzy Punch, but it has a chance to flip two coins
Play your cards right, and you might even be able to summon both of the mighty Link-5 in a single turn