Also look out for cards that generate a stream of expendable tokens like Bitterblossom, and creatures whose value is not in staying on the battlefield but in entering it, like Bone Shredder
Plus, its a creature thats fetchable off a Stoneforge Mystic or the new Cloud, Midgar Mercenary
Even Tanazirs second ability is hard to synergize with the first, since youd rather copy the power of whatever other thing just had its counters doubled
It ramps you, fixes your mana, provides a free artifact for its own metalcraft count, and any other effects in your deck that care about having a number of artifacts in play
If a liquid gets spilled and you have only single sleeved your cards, then the liquid can get into the sleeve and damage cards, youll wish you had double sleeved them