クウィリーオンの獣呼び

If some of the creatures are illegal targets as the second triggered ability tries to resolve, the original distribution of counters still applies and the counters that would have been put on illegal targets are lost.

You choose the targets and announce how the +1/+1 counters will be distributed as you put Quirion Beaastcaller's second ability on the stack. Each target must receive at least one +1/+1 counter.