pyro, neither can be attacked.  But they still do 500 life damage even if they don't attack.
Next play Aqua Chorus(cont. trap). Its effect is 'if there are monsters with the same name

on the field, increase the A and D of all of those monsters with the same name by 500

points'.
This makes the dragons (lv4/A2000/D1500). and they still do 500 life damage each. You

can even play a third Solar Flare Dragon, get the boost, and do a total of 1500 each turn.

all without attacking.
A level 4 monster with 2000A. That would be something,wouldn't it?