These vary from very bad (casting confusion on oneself or drastically lowering their strength) to neutral (leaving glowing footprints) to very good (temporarily learning all Psion spells or gaining universal damage resistance)
On the other hand, quite a few dragons have an ETB effect, which were not that useful there, but you can focus on here
9 Gollum's Bite Black should always have a good instant removal spell on-hand, and Gollums Bite is probably the best in Tales of Middle-earth
Khorvath's FuryKhorvath's Fury is on the weaker side of the spectrum, but we take what we get, right
That doesnt describe very many Constructed formats these days, but if you find yourself in such a meta, you should take a second look at your deck and ask yourself: How many ways do I have to use mana beyond just casting my spells? If your deck gets to the late game consistently, and you have plenty of mana sinks to pour mana into, it stands to reason you might want a higher land count