Each card set usually includes a promo card as a bonus for players, but like the Ancient Mew, most are given away during special events like anniversaries or new releases
Another legendary creature from IV is the turncoat Kain, Traitorous Dragoon
This list is going to have a bit of everything for everyone: broken planeswalkers, historic (if not particularly useful) singles, frequently-reprinted staples, and more
The ultimate is kind of an afterthought here, mostly because you will want to get real cards with the +1, so the mana value of the cards you exile wont be that high, but there will be situations where you look at the board and just using Ashioks +1 twice to exile two expensive things, and then fire off the -7 will make sense
Everything bounces off me and sticks to you: Change the target of target spell or ability that targets only you