Many legendary cards have higher costs to compensate for their stronger abilities, so Kethis giving you a flat one generic mana less cost for them helps get you in the game faster
Melee will trigger if the creature with melee attacks a planeswalker
Saheeli, the Suns Brilliance Listed at: $7.50 Saheeli, the Sun's Brilliance is a token creator that can help you capitalize on your best creatures or artifacts on each turn
This can actively remove threats that are already on the board and also keep opponents from wanting to deploy new ones
However, thats not set to hit stores until 2025, so fans have got a while to wait for that one
The set is available for preorder now from your local game store, online retailers like Amazon, and elsewhere Magic products are sold