This card with the tuner is again good, and with himself (If he can survive a turn) isn't bad either
Though the cards being in Japanese already restrict their usage for Western players, even if youre bilingual theres no chance of mixing the Western and Japanese cards to make a deck due to the big differences in their card backs
Slab has an area where your card sits nicely with a perfect fit sleeve or no sleeve
It would be one thing if it was only doubling its own counters, of which it starts with four, but it doubles the counters on all of your creatures when it attacks
However, if you want a guideline for what kind of cards to look out for, it's good to refer to the Limited archetypes available
Gideon, Ally of Zendikar has been the terror of Standard for far too long, but it is also slowly starting to be adopted in Modern as well