mtg first planeswalker card How Do Planeswalkers Work? ≫ MTG Nicol Bolas, Planeswalker

In this case, your creatures will be gaining +1/+1 (Power/Toughness) counters, and your Planeswalkers will be gaining Loyalty counters

It can be a wall in many circumstances

With Avacyn out, all your permanents gain indestructible, protecting them from all removal except exiling effects

Still, once it resolves, you can choose how to kill your opponent slowly by either casting spells from the top of their library without paying mana, shrinking their hand, killing their creatures, and, if they've survived long enough, exiling all their non-land permanents with the ultimate

* All cards are Mint/NM and in English unless otherwise specified.