Prediction: Tank Items Are Becoming % Scaling Items Rather Than Flat Boosts
Look at this comment in the /dev: State of Champion Update blog regarding the Tank Update:
We also want to take a real hard look at defensive items and how the entire roster (both tanks and non-tanks) engages with them. We want tanks to get a much greater benefit from tank items than other classes, so they can correctly play the role of being the tankiest champions in the game.
Next, look at this comment about Sion and other Tanks in this thread:
We're not planning any changes to Sion specifically. It's likely we'll make some tweaks to defensive base stats on most or all tanks, that'll just be small number changes rather than ability modifications though.
Based on these two quotes, I think it is safe to assume that Riot plans to buff/change Tank base stats to be more powerful defensively and then have Tank items grant % Defensive Stat boosts rather than a flat amount. This way, Tanks will always be tankier than other champions in the game and can be balanced as such.
As in, instead of +50 Armor, you gain +80% Base Armor or something of the sorts.
pretty hard if this happens, cuz his base armor is 16, even at level 18 it's 16.
), so thresh passive giving him base stats instead of bonus ones seems feasible.
