I'm foolishly and fannishly pleased, here in Onmyouji vol 2 (manga), to see that when an Onmyouji is summoning aid he calls on a bunch of heavenly types starting with our friend Tenpou. Googling this I find ASCII art of an onmyouji casting his spell:

【四神相応】
　　∩＿　　　　　
　 [|＿＿]　　　　　南斗北斗三台玉女
　（ | ´∀｀）＿　　　左青龍避万兵
　 |￣|つ￣|　 |つ　右白虎避不詳
　 | ノ　　 | |_ノ　　 前朱雀避口舌
　 |ー――|　　　　 後玄武避万鬼
　/＿＿＿|　　　　前後輔翼　急々如律令！
　 （＿_）＿）　　　

That's him being protected by the four guardian beasts and a few of what I assume to be Daoist types as well. To be found at this site. The top right box there gives you the henpai spell that names the Tenpou-tachi, though I don't see how that scheme a) works or b) has to do with ASCII art. You'll need Japanese enabled of course. (I notice that Tenpou's 天蓬 left out of this version and replaced with 天逢. Either a variant or a typo, I think.)