ho-oh pokemon card first edition – ex 007/034 CLC You may search your deck for a R Energy card and attach it to Ho Pokemon » Ethan's Ho-Oh ex

Today there are many other cast and ETB triggers in mono-Green like the constellation ETB Eidolon of Blossoms or the two-drop shroud Argothian Enchantress as well as things like Enchantress's Presence in enchantment form

In a world where cards entering the battlefield matters more though, flicker or blink effects, which make a card leave the battlefield momentarily only for it to enter the battlefield again, become much better

So just by having them in play, you will gain that lore when you start your turn

It can trigger an ETB for another card for a second time and you can enchant it and deal combat damage reliably

There are more upgrades out there than just the ones mentioned here, but this is a good place to start