One way I can increase the density of combat tricks in Limited is by making creature cards also usable as combat tricks. That's effectively channel, last seen in Kamigawa as on Shinen of Stars' Light.

If I wanted the tricks to cantrip I could instead use cycling triggers like Gempalm Sorcerer. But I think I'd rather these be decent creatures with a not-very-good combat trick alternative, and cycling is always at least reasonably good unless priced prohibitively.

I like that the mechanic name here works well in the flavour of the set: such-and-such soldier can be channelling the Wary Guide she met before by using a defensive technique he taught her.

This card implies a cycle of common creatures with channel, preferably not duplicating any abilities from the cycle of Shinen. First strike is such a natural combat-trick keyword to grant that I'm going to have to be cautious where I use it, so perhaps that'd be lifelink in white.

The other colours aren't so clear. Flying and hexproof are the natural choices for blue, but granting flying and granting hexproof in the Code Geass set are likely to be technological effects, not learned techniques... I could have a ninja like Sayoko who has hexproof, perhaps, which frees up green to be trample. For black deathtouch is natural, though I do want to be cautious how much deathtouch I provide as well. Red, though, doesn't have any good options apart from haste and first strike. I could make a functional reprint of Shinen of Fury's Fire, or I could allow them to branch out into simple non-keyword abilities, something like "Whenever ~ attacks, it gets +2/+0 UEOT. Channel - Discard ~: Target [attacking] creature gets +2/+0 UEOT."

Curiously, this is actually cheaper than any blue hexproof creature printed so far - except for Invisible Stalker which has been declared clearly overpowered. It's Aven Fleetwing without flying or Marchesa's Emissary without dethrone, but cheaper than either. I guess the space of blue hexproof creatures hasn't been explored much - Whirlwind Adept and Benthic Giant are the only other commons there are, though Lone Revenant is more like an uncommon than a rare.

The Channel mode of this is just Mizzium Skin without a couple of options, so I think that's clearly fine.

First stabs at the cycle taken with Compassionate Athlete, Persistent Sergeant, Furious Rebel and Belligerent Brawler.