You may pay U less to play this card from a rune area.
Target up to X resonators you control, where X is the number of different races among resonators you control. Put a [+100/+100] counter on the first. Then repeat this process for each target past the first, adding a [+100/+100] counter each time. (For example, put two counters on the second, three on the third, four on the fourth, etc.)