First, you need enough mana that comes from sources that enter the battlefield untapped, like basic lands or most mana rocks
Deserted Temple Market Price: $5.42 Temple does pretty much nothing on its own but is amazing alongside the most busted lands in the game, essentially acting like a second copy of Gaea's Cradle, Tolarian Academy, Cabal Coffers, Nykthos, Shrine to Nyx, and others that produce multiple pips at once
Secure the Wastes, Assemble the Legion, Myrel, Shield of Argive, and other creature token-producing cards can also amplify Warleaders Calls damage output
Even better you can use Typhlosions ability and attach the enrgy to any pokemon like staraptor or feraligatr and then use charizards ability to bring it to itself
Some platforms are now bridging that gap, blending the convenience of a simulator with the thrill of owning actual, graded cards
It lets you commandeer the activated abilities of creatures in any graveyard, and give them to your creatures, provided they have +1/+1 counters on them