If some of the attacking creatures leave the battlefield while Mangara's triggered ability is on the stack, use the player or planeswalker they were attacking before they left to determine whether you draw a card
Ability costs can include ink (paid by exerting cards in your inkwell), exerted cards (paid by, well, exerting cards) or something else explained on the card itself
The ability to gain chunkier power boosts from Stock Up and Cori-Steel Cutter gives the card an edge over traditional Prowess creatures
It's hard to predict their exact value, particularly in multiplayer
This makes the Lorcana Gateway Box a great way to teach people how to win by having them do it, and while it might be a little bit hands on, certainly compared to most games, its a great way to work around the sink or swim mentality that needs to be employed when you join a game that has been running for several years and has stacked more and more mechanics into it
These powerful cards enable bounce strategies that let you take advantage of effects that happen when cards enter and leave play